Buick Encore Owners & Service Manuals

Buick Encore: Diagnostic information and procedures

Buick Encore 2012-2019 Service Manual / HVAC & Restraints / HVAC - Manual / Diagnostic information and procedures

SCHEMATIC WIRING DIAGRAMS

HVAC WIRING SCHEMATICS (ENCORE)

Power, Ground, and Blower Motor

Fig. 1: Power, Ground, and Blower Motor
Fig. 1: Power, Ground, and Blower Motor

Mode and Temperature Control Actuators

Fig. 2: Mode and Temperature Control Actuators
Fig. 2: Mode and Temperature Control Actuators

Compressor Controls

Fig. 3: Compressor Controls
Fig. 3: Compressor Controls

HVAC WIRING SCHEMATICS (Encore)

Power, Ground, Blower Motor and Air Inlet Actuator

Fig. 4: Power, Ground, Blower Motor and Air Inlet Actuator
Fig. 4: Power, Ground, Blower Motor and Air Inlet Actuator

Compressor Controls (C60)

Fig. 5: Compressor Controls (C60)
Fig. 5: Compressor Controls (C60)

DIAGNOSTIC INFORMATION AND PROCEDURES

HVAC COMPONENT REPLACEMENT REFERENCE (C67)

HVAC Component Replacement Reference (C67)

HVAC Component Replacement Reference (C67)

HVAC Component Replacement Reference (C67)

HVAC COMPONENT REPLACEMENT REFERENCE (C60)

HVAC Component Replacement Reference (C60)

HVAC Component Replacement Reference (C60)

HVAC Component Replacement Reference (C60)

HVAC COMPONENT REPLACEMENT REFERENCE (C41)

HVAC Component Replacement Reference (C41)

HVAC Component Replacement Reference (C41)

DIAGNOSTIC CODE INDEX

DIAGNOSTIC CODE INDEX

DIAGNOSTIC CODE INDEX

DIAGNOSTIC CODE INDEX

DTC B0193: Front blower motor speed circuit

Diagnostic Instructions

  • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
  • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
  • Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC B0193 01

Front Blower Motor Speed Circuit Short to Battery

DTC B0193 06

Front Blower Motor Speed Circuit Low Voltage/Open

Diagnostic Fault Information

Diagnostic Fault Information

Circuit/System Description

The blower motor control module is an interface between the HVAC control module and the blower motor. The blower motor control module has 4 circuits: a B+ input, a signal input from the HVAC control module, a B+ output to the blower motor, and a low side pulse width modulation (PWM) output. The HVAC control module provides a low side (PWM) signal to the blower motor control module in order to request the blower motor speed. The blower motor control module grounds the blower motor using a low side PWM signal in order to vary the blower motor speed.

Conditions for Running the DTC

  • Ignition ON.
  • The HVAC control module is ON.

Conditions for Setting the DTC

B0193 01

The voltage at the HVAC control module output to the blower motor control module is always high.

B0193 06

The voltage at the HVAC control module output to the blower motor control module is always low or fluctuating.

Action Taken When the DTC Sets

The blower motor is inoperative.

Conditions for Clearing the DTC

The condition for setting the DTC is no longer present.

Diagnostic Aids

Inspect the motor shaft for rust or other foreign material which may prohibit proper motor operation.

If the motor operates properly please reinstall it and check for Preliminary Information or Technical Service Bulletins.

Reference Information

Schematic Reference

HVAC Schematics (Encore), HVAC Schematics (Encore)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT

CONNECTOR END VIEWS - INDEX - Encore

Description and Operation

Manual HVAC Description and Operation

Electrical Information Reference

  • Circuit Testing
  • Connector Repairs
  • Testing for Intermittent Conditions and Poor Connections
  • Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Testing

  1. Ignition OFF and all vehicle systems OFF, disconnect the X1 harness connector at the K8 Blower Motor Control Module. It may take up to 2 min for all vehicle systems to power down.
  2. Test for less than 10 ohms between the ground circuit terminal 5 and ground.

If 10 ohms or greater

  1. Ignition OFF.
  2. Test for less than 2 ohms in the ground circuit end to end.
  • If 2 ohms or greater, repair the open/high resistance in the circuit.
  • If less than 2 ohms, repair the open/high resistance in the ground connection.

If less than 10 ohms

  1. Ignition ON.
  2. Verify a test lamp illuminates between the B+ circuit terminal 6 and ground.

If the test lamp does not illuminate and the circuit fuse is good

  1. Ignition OFF, remove the test lamp.
  2. Test for less than 2 ohms in the B+ circuit end to end.
  • If 2 ohms or greater, repair the open/high resistance in the circuit.
  • If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse.

If the test lamp does not illuminate and the circuit fuse is open

  1. Ignition OFF, remove the test lamp.
  2. Test for infinite resistance between the B+ circuit terminal 6 and ground.
  • If less than infinite resistance, repair the short to ground on the circuit.
  • If infinite resistance
  1. Disconnect the X2 harness connector at the K8 Blower Motor Control Module and disconnect the harness connector at the M8 Blower Motor.
  2. Test for infinite resistance between the M8 Blower Motor control circuit terminal B and ground.
  • If less than infinite resistance, repair the short to ground on the circuit.
  • If infinite resistance, test or replace the M8 Blower Motor.

If the test lamp illuminates

  1. Ignition OFF, remove the test lamp.
  2. Test for 2.6-3.2 V between the control circuit terminal 3 and ground.

If less than 2.6 V

  1. Ignition OFF, disconnect the X2 harness connector at the K33 HVAC Control Module, ignition ON.
  2. Test for infinite resistance between the control circuit and ground.
  • If less than infinite resistance, repair the short to ground on the circuit.
  • If infinite resistance.
  1. Test for less than 2 ohms in the control circuit end to end.
  • If 2 ohms or greater, repair the open/high resistance in the circuit.
  • If less than 2 ohms replace the K33 HVAC Control Module

If greater than 3.2 V

  1. Ignition OFF, disconnect the X2 harness connector at the K33 HVAC Control Module, ignition ON.
  2. Test for less than 1 V between the control circuit and ground.
  • If 1 V or greater, repair the short to voltage on the circuit.
  • If less than 1 V, replace the K33 HVAC Control Module.

If between 2.6-3.2 V

  1. Ignition OFF, connect the X1 harness connector at the K8 Blower Motor Control Module and disconnect the harness connector at the M8 Blower Motor, ignition ON and blower ON.
  2. Verify a test lamp illuminates between the control circuit terminal 2 and ground.

If the test lamp does not illuminate

  1. Ignition OFF, remove the test lamp and disconnect the X2 harness connector at the K8 Blower Motor Control Module.
  2. Test for less than 2 ohms in the control circuit end to end.
  • If 2 ohms or greater, repair the open/high resistance in the circuit.
  • If less than 2 ohms replace the K8 Blower Motor Control Module.

If the test lamp illuminates

  1. Connect a test lamp between the control circuit terminal 1 and the control circuit terminal 2.
  2. Verify the test lamp becomes progressively brighter as the blower speed is increased and progressively dimmer as the blower speed is decreased.

If the test lamp does not illuminate

  1. Ignition OFF, remove the test lamp and disconnect the X2 harness connector at the K8 Blower Motor Control Module, ignition ON.
  2. Test for less than 1 V between the control circuit terminal 2 and ground.
  • If 1 V or greater, repair the short to voltage on the circuit.
  • If less than 1 V
  1. Ignition OFF.
  2. Test for less than 2 ohms in the control circuit end to end.
  • If 2 ohms or greater, repair the open/high resistance in the circuit.
  • If less than 2 ohms replace the K8 Blower Motor Control Module.

If the test lamp illuminates, but does not change in brightness

  1. Ignition OFF, remove the test lamp and disconnect the X2 harness connector at the K8 Blower Motor Control Module.
  2. Test for infinite resistance between the control circuit terminal 2 and ground.
  • If less than infinite resistance, repair the short to ground on the circuit.
  • If infinite resistance, replace the K8 Blower Motor Control Module.

If the test lamp changes in brightness as the blower speed is changed

  1. Test or replace the M8 Blower Motor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

  • HVAC Component Replacement Reference (C67), HVAC Component Replacement Reference (C60), HVAC Component Replacement Reference (C41)
  • Control Module References for HVAC control module replacement, programming and setup

DTC B0223 (C60): Recirculate position command 1 circuit

Diagnostic Instructions

  • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
  • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
  • Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC B0223 01

Recirculate Position Command 1 Circuit Short to Battery

DTC B0223 02

Recirculate Position Command 1 Circuit Short to Ground

DTC B0223 04

Recirculate Position Command 1 Circuit Open

Diagnostic Fault Information

Diagnostic Fault Information

Circuit/System Description

The air inlet actuator is a 2-wire bi-directional electric motor. There are two control circuits that enable the actuator to operate. The control circuits use either a ground or 12 V value to coordinate the actuator movement.

When the actuator is at rest, both control circuits have a value of approximately 0 V. In order to move the actuator, the HVAC control module grounds one of the control circuits while providing the other with 12 V.

The HVAC control module reverses the polarity of the control circuits to move the actuator in the opposite direction.

Conditions for Running the DTC

Ignition ON

Conditions for Setting the DTC

B0223 01

The HVAC control module detects a short to battery in either air inlet control circuit.

B0223 02

The HVAC control module detects a short to ground in either air inlet control circuit.

B0223 04

The HVAC control module detects an open in an either inlet control circuit.

Action Taken When the DTC Sets

The air inlet door will be inoperative.

Reference Information

Schematic Reference

HVAC Schematics (Encore), HVAC Schematics (Encore)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - Encore

Description and Operation

Manual HVAC Description and Operation

Electrical Information Reference

  • Circuit Testing
  • Connector Repairs
  • Testing for Intermittent Conditions and Poor Connections
  • Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

  1. Ignition ON.
  2. Verify the M4 Air Inlet Door Actuator moves between the RECIRCULATE and FRESH AIR positions within 10 s when pressing the recirculation switch.
  • If the M4 Air Inlet Door Actuator does not move between the RECIRCULATE and FRESH AIR positions

Refer to Circuit/System Testing

  • If the M4 Air Inlet Door Actuator moves between the RECIRCULATE and FRESH AIR positions
  1. Verify the M4 Air Inlet Door Actuator returns to its previous position within 10 s when pressing the recirculation switch.
  • If the M4 Air Inlet Door Actuator does not return to its previous position

Refer to Circuit/System Testing.

  • If the M4 Air Inlet Door Actuator does return to its previous position
  1. All OK.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the M4 Air Inlet Door Actuator.
  2. Connect a test lamp between control circuit terminal A and control circuit terminal B, ignition ON.
  3. Verify the test lamp turns ON for approximately 10 s when commanding the Air Recirculation Mode Switch On and Off with a scan tool

If the test lamp does not turn ON and OFF during either of the commands

  1. Ignition OFF, remove the test lamp and disconnect the X3 harness connector at the K33 HVAC Control Module, ignition ON.
  2. Test for less than 1 V between each control circuit and ground.
  • If 1 V or greater, repair the short to voltage on the circuit.
  • If less than 1 V
  1. Test for infinite resistance between each control circuit and ground.
  • If less than infinite resistance, repair the short to ground on the circuit.
  • If infinite resistance
  1. Test for infinite resistance between the control circuits.
  • If less than infinite resistance, repair the short on the circuit.
  • If infinite resistance
  1. Test for less than 2 ohms in each control circuit end to end.
  • If 2 ohms or greater, repair the open/high resistance in the circuit.
  • If less than 2 ohms, replace the K33 HVAC Control Module.

If the test lamp turns ON and OFF during each of the commands

  1. Test or replace the M4 Air Inlet Door Actuator.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

  • HVAC Component Replacement Reference (C67), HVAC Component Replacement Reference (C60), HVAC Component Replacement Reference (C41)
  • Control Module References for HVAC control module replacement, programming and setup

DTC B0223, B0233, B023A, OR B0408 (C67): Recirculate position command 1 circuit/airflow control circuit/actuators supply voltage

Diagnostic Instructions

  • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
  • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
  • Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC B0223 01

Recirculate Position Command 1 Circuit Short to Battery

DTC B0223 06

Recirculate Position Command 1 Circuit Low Voltage/Open

DTC B0233 01

Air Flow Control Circuit Short to Battery

DTC B0233 06

Air Flow Control Circuit Low Voltage/Open

DTC B023A 02

HVAC Actuators Supply Voltage Short to Ground

DTC B0408 01

Main Temperature Control Circuit Short to Battery

DTC B0408 06

Main Temperature Control Circuit Low Voltage/Open

Diagnostic Fault Information

Diagnostic Fault Information

Diagnostic Fault Information

Circuit/System Description

Stepper motors are used for temperature regulation, air distribution control, and recirculation door control.

With the switches, buttons, and dials on the HVAC controls, air temperature door position, mode door position, and recirculation door position can be selected. The selected values are passed to the HVAC control module via serial data. The HVAC control module supplies a switched 12 V control voltage to the stepper motors and energizes the 4 stepper motor coils with a pulsed ground signal. The stepper motors move the appropriate doors to the requested positions.

Conditions for Running the DTC

  • Ignition ON.
  • The HVAC control module is ON.

Conditions for Setting the DTC

B023A 02

The stepper motors supply output is shorted to ground.

B0223 01, B0233 01, B023A 01, or B0408 01

At least one control circuits of the appropriate stepper motor is shorted to voltage when motor starts moving.

Faults are not detected when motor is already running or target position is already reached.

B0223 06, B0233 06, B0233 06, or B0408 06

At least one control circuits of the appropriate stepper motor is shorted to ground or open when motor starts moving. Faults are not detected when motor is already running or target position is already reached.

Action Taken When the DTC Sets

B023A 02

  • The affected output will be switched off for hardware protection.
  • All stepper motors are deactivated.

B0223, B0233, B023A, or 0408

  • The affected output will be switched off for hardware protection.
  • The affected stepper motor is deactivated.

Conditions for Clearing the DTC

The condition for setting the DTC is no longer present.

Reference Information

Schematic Reference

HVAC Schematics (Encore), HVAC Schematics (Encore)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - Encore

Description and Operation

Manual HVAC Description and Operation

Electrical Information Reference

  • Circuit Testing
  • Connector Repairs
  • Testing for Intermittent Conditions and Poor Connections
  • Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

  1. Perform the Actuator Recalibration (C67) procedure.
  2. Verify the concern or DTC has been corrected.

If the concern or DTC has not been corrected

  1. Verify DTC B023A is not set.
  • If DTC B023A is set, refer to Circuit/System Testing - DTC B023A.
  • If DTC B023A is not set, refer to Circuit/System Testing - DTC B0223, B022A, B0233, or B0408.

If the concern or DTC has been corrected

  1. All OK.

Circuit/System Testing

DTC B023A

  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the components listed below. It may take up to 2 min for all vehicle systems to power down.
  • M37 Mode Door Actuator
  • M46 Air Recirculation Door Actuator
  • M6 Air Temperature Door Actuator
  1. Disconnect the harness connector at the K33 HVAC Control Module.
  2. Test for infinite resistance between the K33 HVAC Control Module 12 V reference circuit terminal 15 and ground.

If less than infinite resistance

Repair the short to ground on the circuit.

If infinite resistance

  1. Ignition ON.
  2. Test for less than 1 V between the K33 HVAC Control Module 12 V reference circuit terminal 15 and ground.

If 1 V or greater

Repair the short to voltage on the circuit.

If less than 1 V

  1. Connect the harness connector at the K33 HVAC Control Module, ignition ON.
  2. Clear all DTCs.
  3. Verify DTC B023A is not set.

If the DTC is set.

Replace the K33 HVAC Control Module.

If the DTC is not set.

  1. Verify DTC B023A does not set after connecting each of the components listed below one at a time and operating them through their full range.
  • M37 Mode Door Actuator
  • M46 Air Recirculation Door Actuator
  • M6 Air Temperature Door Actuator
  • If the DTC sets after connecting one of the components

Replace the component that was connected immediately before the DTC set.

If the DTC does not set

  1. All OK.

DTC B0223, B022A, B0233, or B0408

  1. Ignition OFF, disconnect the harness connector at the appropriate door actuator, ignition ON.
  2. Verify a test lamp flashes when connected between the 12 V reference circuit terminal 2 and ground.

If the test lamp does not flash

  1. Ignition OFF, remove the test lamp and disconnect the harness connector at the K33 HVAC Control Module.
  2. Test for less than 2 ohms in the 12 V reference circuit end to end.
  • If 2 ohms or greater, repair the open/high resistance in the circuit.
  • If less than 2 ohms, replace the K33 HVAC Control Module.

If the test lamp flashes

  1. Connect a test lamp between each control circuit listed below and B+.
  • Control Circuit - terminal 1
  • Control Circuit - terminal 3
  • Control Circuit - terminal 4
  • Control Circuit - terminal 6
  1. Command the appropriate door actuator in both directions.
  2. Verify the test lamp turns ON and then OFF during at least one of the directional commands

If the test lamp is always ON

  1. Ignition OFF, remove the test lamp and disconnect the harness connector at the K33 HVAC Control Module.
  2. Test for infinite resistance between the control circuit and ground.
  • If less than infinite resistance, repair the short to ground on the circuit.
  • If infinite resistance, replace the K33 HVAC Control Module.

If the test lamp is always OFF

  1. Ignition OFF, remove the test lamp and disconnect the harness connector at the K33 HVAC Control Module, ignition ON.
  2. Test for less than 1 V between the control circuit and ground.
  • If 1 V or greater, repair the short to voltage on the circuit.
  • If less than 1 V
  1. Ignition OFF
  2. Test for less than 2 ohms in the control circuit end to end.
  • If 2 ohms or greater, repair the open/high resistance is the circuit.
  • If less than 2 ohms, replace the K33 HVAC Control Module.

If the test lamp turns ON and then OFF

  1. Replace the door actuator.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

  • HVAC Component Replacement Reference (C67)
  • Control Module References for HVAC control module replacement, programming and setup

DTC B3933: Air conditioning evaporator temperature sensor

Diagnostic Instructions

  • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
  • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
  • Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC B3933 02

Air Conditioning Evaporator Temperature Sensor Circuit Short to Ground

DTC B3933 05

Air Conditioning Evaporator Temperature Sensor Circuit High Voltage/Open

Diagnostic Fault Information

Diagnostic Fault Information

Circuit/System Description

The evaporator air temperature sensor is a 2-wire negative temperature coefficient thermistor which operates using signal and low reference circuits. As the air temperature surrounding the sensor increases, the sensor resistance decreases. The sensor is capable of reading temperatures ranging from -40 to +80ºC (-40 to +176ºF), with a signal voltage between 0-5 V. If the HVAC control module detects a malfunctioning sensor the software uses a default air temperature value. The default action ensures that the HVAC system can adjust the inside air temperature near the desired temperature until the condition is corrected.

Conditions for Running the DTC

  • Ignition ON.
  • The HVAC control module is ON.

Conditions for Setting the DTC

The HVAC control module detects the sensor signal out of range. The signal voltage is less than 0.1 V or greater than 4.9 V for more than 50 ms.

Action Taken When the DTC Sets

The system operates using a default value.

Conditions for Clearing the DTC

The sensor signal is within specified range between 0.1-4.9 V.

Reference Information

Schematic Reference

HVAC Schematics (Encore), HVAC Schematics (Encore)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - Encore

Description and Operation

Manual HVAC Description and Operation

Electrical Information Reference

  • Circuit Testing
  • Connector Repairs
  • Testing for Intermittent Conditions and Poor Connections
  • Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Testing

  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the B39 A/C Evaporator Temperature Sensor. It may take up to 10 min for all vehicle systems to power down.

NOTE: The scan tool must be disconnected from the vehicle before performing the next test.

  1. Test for less than 10 ohms between the low reference circuit terminal B and ground.

If 10 ohms or greater

  1. Ignition OFF, disconnect the harness connector at the K33 HVAC Control Module.
  2. Test for less than 2 ohms in the low reference circuit end to end.
  • If 2 ohms or greater, repair the open/high resistance in the circuit.
  • If less than 2 ohms, replace the K33 HVAC Control Module.

If less than 10 ohms

  1. Test for 4.8-5.2 V between the signal circuit terminal A and ground.

If less than 4.8 V

  1. Ignition OFF, disconnect the harness connector at the K33 HVAC Control Module.
  2. Test for infinite resistance between the signal circuit and ground.
  • If less than infinite resistance, repair the short to ground on the circuit.
  • If infinite resistance
  1. Test for less than 2 ohms in the signal circuit end to end.
  • If 2 ohms or greater, repair the open/high resistance in the circuit.
  • If less than 2 ohms, replace the K33 HVAC Control Module.

If greater than 5.2 V

  1. Ignition OFF, disconnect the harness connector at the K33 HVAC Control Module, ignition ON.
  2. Test for less than 1 V between the signal circuit and ground.
  • If 1 V or greater, repair the short to voltage on the circuit.
  • If less than 1 V, replace the K33 HVAC Control Module.

If between 4.8-5.2 V

  1. Test or replace the B39 A/C Evaporator Temperature Sensor.
  2. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  3. Verify the DTC does not set.

If the DTC sets

Replace the K33 HVAC Control Module.

If the DTC does not set

  1. All OK

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

  • HVAC Component Replacement Reference (C67), HVAC Component Replacement Reference (C60), HVAC Component Replacement Reference (C41)
  • Control Module References for HVAC control module replacement, programming and setup

DTC P0532 OR P0533: Air conditioning (A/C) Refrigerant pressure sensor

Diagnostic Instructions

  • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
  • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
  • Diagnostic Procedure Instructions provides an overview of the diagnostic category.

DTC Descriptors

DTC P0532

Air Conditioning (A/C) Refrigerant Pressure Sensor Circuit Low Voltage

DTC P0533

Air Conditioning (A/C) Refrigerant Pressure Sensor Circuit High Voltage

Diagnostic Fault Information

Diagnostic Fault Information

Circuit/System Description

The engine control module (ECM) monitors the high side refrigerant pressure through the A/C refrigerant pressure sensor. The ECM supplies a 5 V reference and a low reference to the sensor. Changes in the A/C refrigerant pressure cause the sensor signal to the ECM to vary. When the pressure is high, the signal voltage is high. When the pressure is low, the signal voltage is low. The ECM may use this information to turn the cooling fans on as well as to monitor clutch engagement. The HVAC module will receive the A/C refrigerant pressure information from the ECM via serial data.

Conditions for Running the DTC

  • Engine is running.
  • Any of the conditions for setting the DTC are met for 15 s.
  • Battery voltage is between 11-18 V.

Conditions for Setting the DTC

P0532

The ECM detects that the A/C pressure is less than 1 psi (0.25 V).

P0533

The ECM detects that the A/C pressure is more than 428 psi (4.92 V).

Action Taken When the DTC Sets

  • The A/C compressor is disabled.
  • The ECM will illuminate the malfunction indicator lamp (MIL).

Conditions for Clearing the DTC

The condition for setting the DTC is no longer present.

Diagnostic Aids

A malfunction within the refrigerant system causing high pressure can cause this DTC to set.

Reference Information

Schematic Reference

HVAC Schematics (Encore), HVAC Schematics (Encore)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - Encore

Description and Operation

Manual HVAC Description and Operation

Electrical Information Reference

  • Circuit Testing
  • Connector Repairs
  • Testing for Intermittent Conditions and Poor Connections
  • Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (LUV) , Powertrain Diagnostic Trouble Code (DTC) Type Definitions (2H0)

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

  1. Ignition ON
  2. Verify the scan tool ECM A/C High Side Pressure Sensor parameter is between 6.8 kPa (1 psi) and 2950 kPa (428 psi).

If not between 6.8 kPa (1 psi) and 2950 kPa (428 psi)

Refer to Circuit/System Testing

If between 6.8 kPa (1 psi) and 2950 kPa (428 psi)

  1. All OK

Circuit/System Testing

  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the B1 A/C Refrigerant Pressure Sensor. It may take up to 2 min for all vehicle systems to power down.
  2. Test for less than 10 ohms between the low reference circuit terminal 1 and ground.

If 10 ohms or greater

  1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
  2. Test for less than 2 ohms in the low reference circuit end to end.
  • If 2 ohms or greater, repair the open/high resistance in the circuit.
  • If less than 2 ohms, replace the K20 Engine Control Module.

If less than 10 ohms

  1. Ignition ON.
  2. Test for 4.8-5.2 V between the 5 V reference circuit terminal 2 and ground.

If less than 4.8 V

  1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
  2. Test for infinite resistance between the 5 V reference circuit and ground
  • If less than infinite resistance, repair the short to ground on the circuit.
  • If infinite resistance
  1. Test for less than 2 ohms in the 5 V reference circuit end to end.
  • If 2 ohms or greater, repair the open/high resistance in the circuit.
  • If less than 2 ohms, replace the K20 Engine Control Module.

If greater than 5.2 V

  1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON.
  2. Test for less than 1 V between the 5 V reference circuit and ground.
  • If 1 V or greater, repair the short to voltage on the circuit.
  • If less than 1 V, replace the K20 Engine Control Module

If between 4.8-5.2 V

  1. Verify the scan tool ECM A/C High Side Pressure Sensor parameter is less than .25 V.

If .25 V or greater

  1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON.
  2. Test for less than 1 V between the signal circuit terminal 3 and ground.
  • If 1 V or greater, repair the short to voltage on the circuit.
  • If less than 1 V, replace the K20 Engine Control Module

If less than .25 V

  1. Install a 3 A fused jumper wire between the signal circuit terminal 3 and the 5 V reference circuit terminal 2.
  2. Verify the scan tool ECM A/C High Side Pressure Sensor parameter is greater than 4.8 V.

If 4.8 V or less

  1. Ignition OFF, remove the jumper wire, disconnect the harness connector at the K20 Engine Control Module.
  2. Test for infinite resistance between the signal circuit terminal 3 and ground.
  • If less than infinite resistance, repair the short to ground on the circuit.
  • If infinite resistance
  1. Test for less than 2 ohms in the signal circuit end to end.
  • If 2 ohms or greater, repair the open/high resistance in the circuit.
  • If less than 2 ohms, replace the K20 Engine Control Module.

If greater than 4.8 V

  1. Test or replace the B1 A/C Refrigerant Pressure Sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

  • HVAC Component Replacement Reference (C67), HVAC Component Replacement Reference (C60), HVAC Component Replacement Reference (C41)
  • Control Module References for engine control module replacement, programming and setup

DTC P0645, P0646, OR P0647: Air conditioning (A/C) compressor clutch relay

Diagnostic Instructions

  • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
  • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
  • Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC P0645

Air Conditioning (A/C) Compressor Clutch Relay Control Circuit

DTC P0646

Air Conditioning (A/C) Compressor Clutch Relay Control Circuit Low Voltage

DTC P0647

Air Conditioning (A/C) Compressor Clutch Relay Control Circuit High Voltage

Diagnostic Fault Information

Diagnostic Fault Information

Circuit/System Description

When the A/C switch is pressed, the HVAC control module sends a serial data message to the engine control module (ECM) indicating the A/C request. In response to this message, the ECM grounds the A/C compressor clutch relay control circuit energizing the A/C compressor clutch relay. With the relay contacts closed, battery voltage is applied through the A/C compressor clutch control circuit activating the A/C compressor clutch.

Conditions for Running the DTC

  • The ignition voltage is between 11-18 volts.
  • The engine speed is greater than 600 RPM.
  • An A/C request is made.

Conditions for Setting the DTC

P0645 or P0646

The ECM detects a short to ground or an open at the A/C compressor clutch relay control circuit.

P0647

The ECM detects a short to voltage at the A/C compressor clutch relay control circuit.

Action Taken When the DTC Sets

P0645 or P0646

The A/C compressor is inoperative or always active.

P0647

The A/C compressor is inoperative.

Conditions for Clearing the DTC

A history DTC clears after 40 consecutive warm-up cycles have occurred without a malfunction.

Reference Information

Schematic Reference

HVAC Schematics (Encore), HVAC Schematics (Encore)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - Encore

Description and Operation

Manual HVAC Description and Operation

Electrical Information Reference

  • Circuit Testing
  • Connector Repairs
  • Testing for Intermittent Conditions and Poor Connections
  • Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (LUV) , Powertrain Diagnostic Trouble Code (DTC) Type Definitions (2H0)

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Testing

  1. Ignition OFF, and all vehicle systems OFF. Disconnect the harness connector at the Q2 A/C Compressor Clutch. It may take up to 2 min for all vehicle systems to power down.
  2. Test for less than 10 ohms between the Q2 A/C Compressor Clutch ground circuit terminal A and ground

If 10 ohms or greater

  1. Ignition OFF.
  2. Test for less than 2 ohms in the ground circuit end to end.
  • If 2 ohms or greater, repair the open/high resistance in the circuit.
  • If less than 2 ohms, repair the open/high resistance in the ground connection.

If less than 10 ohms

  1. Connect a test lamp between the control circuit terminal B and ground, ignition ON.
  2. Verify the test lamp does not turn ON and OFF when commanding the Q2 A/C Compressor Clutch On and Off with a scan tool.

If the test lamp turns ON and OFF

Test or replace the Q2 A/C Compressor Clutch.

If the test lamp does not turn ON and OFF

  1. Ignition OFF, connect the harness connector at the Q2 A/C Compressor Clutch. Disconnect the X3 harness connector at the X50A Fuse Block - Underhood, ignition ON.
  2. Verify the Q2 A/C Compressor Clutch is not activated.

If the Q2 A/C Compressor Clutch is activated

  1. Ignition OFF, disconnect the harness connector at the Q2 A/C Compressor Clutch, ignition ON.
  2. Test for less than 1 V between the control circuit terminal B and ground.
  • If 1 V or greater, repair the short to voltage on the circuit.
  • If less than 1 V, test or replace the Q2 A/C Compressor Clutch.

If the Q2 A/C Compressor Clutch is not activated

  1. Connect a 10 A fused jumper wire between the control circuit terminal B5 and B+.
  2. Verify the Q2 A/C Compressor Clutch activates

If the Q2 A/C Compressor Clutch does not activate

  1. Ignition OFF, remove the jumper wire, disconnect the harness connector at the Q2 A/C Compressor Clutch, ignition ON.
  2. Test for infinite resistance between the control circuit and ground.
  • If less than infinite resistance, repair the short to ground on the circuit.
  • If infinite resistance
  1. Test for less than 2 ohms in the control circuit end to end.
  • If 2 ohms or greater, repair the open/high resistance in the circuit.
  • If less than 2 ohms, test or replace the Q2 A/C Compressor Clutch.

If the Q2 A/C Compressor Clutch activates

  1. Ignition OFF, connect the X3 harness connector at the X50A Fuse Block - Underhood and disconnect the harness connector at the K20 Engine Control Module, ignition ON.
  2. Verify the Q2 A/C Compressor Clutch is not activated.

If the Q2 A/C Compressor Clutch is activated

  1. Ignition OFF, disconnect the X3 harness connector at the X50A Fuse Block - Underhood.
  2. Test for infinite resistance between the X3 X50A Fuse Block - Underhood control circuit terminal B4 and ground.
  • If less than Infinite resistance, repair the short to ground on the circuit.
  • If infinite resistance, test or replace the X50A Fuse Block - Underhood.

If the Q2 A/C Compressor Clutch is not activated

  1. Connect a 3 A fused jumper wire between the K20 Engine Control Module control circuit terminal for the KR29 A/C Compressor Clutch Relay and ground.
  2. Verify the Q2 A/C Compressor Clutch activates.

If the Q2 A/C Compressor Clutch does not activate

  1. Ignition OFF, remove the jumper wire, disconnect the X3 harness connector at the X50A Fuse Block - Underhood, ignition ON.
  2. Test for less than 1 V between the X3 X50A Fuse Block - Underhood control circuit terminal B4 and ground.
  • If 1 V or greater, repair the short to voltage on the circuit.
  • If less than 1 V
  1. Test for less than 2 ohms in the control circuit end to end.
  • If 2 ohms or greater, repair the open/high resistance in the circuit.
  • If less than 2 ohms, test or replace the X50A Fuse Block - Underhood.

If the Q2 A/C Compressor Clutch activates

  1. Replace the K20 Engine Control Module.

Component Testing

Compressor Clutch Test

  1. Ignition OFF, disconnect the Q2 A/C Compressor Clutch.
  2. Test for 3.9 - 4.3 ohms between terminal A and terminal B.

If not between 3.9 - 4.3 ohms

Replace the Q2 A/C Compressor Clutch.

If between 3.9 - 4.3 ohms

  1. Test for infinite resistance between terminal A and ground.

If less than infinite resistance

Replace the Q2 A/C Compressor Clutch.

If infinite resistance

  1. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

  • HVAC Component Replacement Reference (C67), HVAC Component Replacement Reference (C60), HVAC Component Replacement Reference (C41)
  • Front Compartment Fuse Block Replacement
  • Control Module References for engine control module replacement, programming and setup

Symptoms - HVAC Systems - manual

NOTE: The following steps must be completed before using the symptom tables:

  1. Perform the Diagnostic System Check - Vehicle before using the HVAC System Malfunction procedure in order to verify that all of the following are true:
  • There are no DTCs set.
  • The control modules can communicate via the serial data link.
  1. Review the system operation in order to familiarize yourself with the system functions. Refer to Manual HVAC Description and Operation.

Visual/Physical Inspection

  • Inspect for aftermarket devices which may affect the operation of the HVAC System. Refer to Checking Aftermarket Accessories .
  • Inspect the easily accessible or visible system components for obvious damage or conditions which may cause the symptom.
  • Verify the A/C compressor turns freely and is not seized.
  • Verify that the customer is using the correct key to enable personalization and is not inadvertently activating auxiliary HVAC controls.
  • The A/C compressor will not operate in cold outside air temperatures.
  • The following conditions may cause window fogging:
  • Wet carpet or mats
  • High humidity
  • Interior water leak
  • Blocked A/C evaporator drain tube
  • Maximum passenger capacity
  • Blocked body pressure relief valves
  • Inspect the air distribution system for causes of reduced air flow:
  • Obstructed or dirty passenger compartment air filter, if equipped
  • Blocked or damaged air inlet or outlet vents

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections .

Symptom List

Refer to HVAC System Malfunction (C60), HVAC System Malfunction (C67), HVAC System Malfunction (C41) in order to diagnose the symptom:

HVAC System malfunction (C60)

Diagnostic Instructions

  • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
  • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
  • Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Diagnostic Aids

Check the following mechanical fault sources

  • Air distribution box
  • Air distribution hoses/air distribution ducts
  • Mode and temperature door cables

Reference Information

Schematic Reference

HVAC Schematics (Encore), HVAC Schematics (Encore)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - Encore

Description and Operation

Manual HVAC Description and Operation

Electrical Information Reference

  • Circuit Testing
  • Connector Repairs
  • Testing for Intermittent Conditions and Poor Connections
  • Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J43600 ACR Air Conditioning Service Center

Circuit/System Verification

NOTE: Check for bulletins before proceeding.

  1. Ignition ON.
  2. Verify every applicable scan tool Switch parameter changes when pressing the appropriate switch on the A26 HVAC Controls.

If any parameter does not change

Replace the A26 HVAC Controls.

If all parameters change

  1. Verify the blower motor operates properly with the blower motor switch in each speed position.
  • If the blower motor does not operate in each speed position

Refer to Blower Motor Malfunction (C41, C60).

  • If the blower motor operates properly in each speed position
  1. Verify the air inlet door works properly when commanded.
  • If the air inlet door does not work properly

Refer to DTC B0223 (C60)

  • If the air inlet door does work properly
  1. Install the J43600 ACR Air Conditioning Service Center, ignition ON.
  2. Verify the high side pressure reading on the Air Conditioning Service Center is within 10% of the scan tool ECM A/C High Side Pressure Sensor parameter.

If the reading is not within 10%

Refer to DTC P0532 or P0533.

If the reading is within 10%

  1. Verify the ECM A/C High Side Pressure Sensor parameter is between 269-2929 kPa (39-425 PSI).

If the reading is not between 269-2929 kPa (39-425 PSI)

Refer to Air Conditioning (A/C) System Performance Test

If the reading is between 269-2929 kPa (39-425 PSI)

  1. Verify the scan tool HVAC A/C Evaporator Temperature Sensor parameter listed is within 10% of ambient temperature.

If not within 10% of ambient temperature

Refer to DTC B3933.

If within 10% of ambient temperature

  1. Verify the A/C compressor clutch engages and disengages when commanding the ECM A/C Compressor Clutch Relay On and Off with a scan tool.

If the A/C compressor does not engage

Refer to DTC P0645, P0646, or P0647

If the A/C compressor does engage

  1. Engine ON, A/C system ON.
  2. Verify cool air flows from the ducts with the temperature control in the coldest position.

If the air is not cool

  1. Verify the Q2 A/C Compressor Clutch is engaged.
  • If the Q2 A/C Compressor Clutch is not engaged, refer to Air Conditioning Compressor Malfunction (C60).
  • If the Q2 A/C Compressor Clutch is engaged, refer to Air Conditioning (A/C) System Performance Test .

If the air is cool

  1. Verify warm air flows from the ducts with the temperature control in the warmest position.

If the air is not warm

Refer to Heating Performance Diagnostic

If the air is warm

  1. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

  • HVAC Component Replacement Reference (C60)
  • Control Module References for HVAC control module replacement, programming and setup

HVAC System malfunction (C67)

Diagnostic Instructions

  • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
  • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
  • Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Diagnostic Aids

Check the following mechanical fault sources:

  • Air distribution box
  • Air distribution hoses/air distribution ducts

Reference Information

Schematic Reference

HVAC Schematics (Encore), HVAC Schematics (Encore)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - Encore

Description and Operation

Manual HVAC Description and Operation

Electrical Information Reference

  • Circuit Testing
  • Connector Repairs
  • Testing for Intermittent Conditions and Poor Connections
  • Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J43600 ACR Air Conditioning Service Center

Circuit/System Verification

NOTE: Check for bulletins before proceeding.

  1. Ignition ON.
  2. Verify every applicable scan tool Switch parameter changes when pressing the appropriate switch on the A26 HVAC Controls.

If any parameter does not change

Replace the A26 HVAC Controls.

If all parameters change

  1. Verify the blower motor operates properly with the blower motor switch in each speed position.

If the blower motor does not operate in each speed position

Refer to DTC B0193.

If the blower motor operates properly in each speed position

  1. Verify the HVAC doors listed below move when pressing the appropriate switch.
  • Temperature
  • Mode
  • Recirculation

If any HVAC door does not move

Refer to DTC B0223, B0233, B023A, or B0408 (C67)

If all HVAC doors move

  1. Install the J43600 ACR Air Conditioning Service Center, ignition ON.
  2. Verify the high side pressure reading on the Air Conditioning Service Center is within 10% of the scan tool ECM A/C High Side Pressure Sensor parameter.

If the reading is not within 10%

Refer to DTC P0532 or P0533.

If the reading is within 10%

  1. Verify the HVAC A/C High Side Pressure Sensor parameter is between 269-2929 kPa (39-425 PSI).

If the reading is not between 269-2929 kPa (39-425 PSI)

Refer to Air Conditioning (A/C) System Performance Test

If the reading is between 269-2929 kPa (39-425 PSI)

  1. Verify the scan tool HVAC A/C Evaporator Temperature Sensor parameter listed is within 10% of ambient temperature.

If not within 10% of ambient temperature

Refer to DTC B3933.

If within 10% of ambient temperature

  1. Verify the A/C compressor clutch engages and disengages when commanding the ECM A/C Compressor Clutch Relay On and Off with a scan tool.

If the A/C compressor does not engage

Refer to DTC P0645, P0646, or P0647

If the A/C compressor does engage

  1. Engine ON, A/C system ON
  2. Verify cool air flows from the ducts with the temperature control in the coldest position.

If the air is not cool

  1. Verify the Q2 A/C Compressor Clutch is engaged.
  • If the Q2 A/C Compressor Clutch is not engaged, refer to Air Conditioning Compressor Malfunction (C67).
  • If the Q2 A/C Compressor Clutch is engaged, refer to Air Conditioning (A/C) System Performance Test .

If the air is cool

  1. Verify warm air flows from the ducts with the temperature control in the warmest position.

If the air is not warm

Refer to Heating Performance Diagnostic .

If the air is warm

  1. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

  • HVAC Component Replacement Reference (C67)
  • Control Module References for HVAC control module replacement, programming and setup

HVAC System malfunction (C41)

Diagnostic Instructions

  • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
  • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
  • Diagnostic Procedure Instructions provides an overview of each diagnostic category

Diagnostic Aids

Check the following mechanical fault sources:

  • Air distribution box
  • Air distribution hoses/air distribution ducts
  • Mode and temperature door cables

Reference Information

Schematic Reference

HVAC Schematics (Encore), HVAC Schematics (Encore)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - Encore

Description and Operation

Manual HVAC Description and Operation

Electrical Information Reference

  • Circuit Testing
  • Connector Repairs
  • Testing for Intermittent Conditions and Poor Connections
  • Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

NOTE: Check for bulletins before proceeding.

  1. Ignition ON.
  2. Verify the blower motor operates properly with the blower motor switch in each speed position.

If the blower motor does not operate in each speed position

Refer to Blower Motor Malfunction (C41, C60).

If the blower motor operates properly in each speed position

  1. Verify warm air flows from the ducts with the temperature control in the warmest position.

If the air is not warm

Refer to Heating Performance Diagnostic .

If the air is warm

  1. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

  • HVAC Component Replacement Reference (C41)
  • Control Module References for HVAC control module replacement, programming and setup

Air conditioning compressor malfunction (C60)

Diagnostic Instructions

  • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
  • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
  • Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Diagnostic Fault Information

Diagnostic Fault Information

Circuit/System Description

The A/C compressor uses a conventional belt driven magnetic clutch to engage and mechanically turn the compressor. When the A/C switch is pressed, the HVAC control module sends an A/C request message to the ECM via serial data. If specific criteria are met, the ECM then grounds the A/C compressor clutch relay control circuit, which will switch the A/C compressor clutch relay. With the relay contacts closed, battery voltage is supplied to the permanently grounded A/C compressor clutch. The A/C compressor clutch will then be activated.

Diagnostic Aids

The following conditions must be met in order to turn on the A/C compressor:

  • Battery voltage is between 9-18 V.
  • Engine coolant temperature is less than 124ºC (255ºF).
  • Engine speed is greater than 600 RPM.
  • Engine speed is less than 5 500 RPM.
  • A/C high side pressure is between 269-2 929 kPa (39-425 PSI).
  • Throttle position is less than 100%.
  • Evaporator temperature is greater than 3ºC (38ºF).
  • ECM does not detect excessive torque load.
  • ECM does not detect insufficient idle quality.
  • The ambient temperature is above 1ºC (34ºF).
  • Blower motor must be in any other position than off.
  • A/C switch is depressed.

Reference Information

Schematic Reference

HVAC Schematics (Encore), HVAC Schematics (Encore)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - Encore

Description and Operation

Manual HVAC Description and Operation

Electrical Information Reference

  • Circuit Testing
  • Connector Repairs
  • Testing for Intermittent Conditions and Poor Connections
  • Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

NOTE: Refer to HVAC System Malfunction (C60) before performing this procedure

  1. Ignition ON, press and release the A/C switch several times.
  2. Verify the HVAC control module scan tool A/C Switch parameter changes between Active and Inactive

If the parameter does not change

Replace the K33 HVAC Control Module.

If the parameter changes

  1. Set A/C system to coolest setting with blower ON.
  2. Press and release the A/C switch several times.
  3. Verify the ECM scan tool A/C Request Signal parameter changes between YES and NO.

If the parameter does not change

Refer Circuit/System Testing

If the parameter changes

  1. Verify the A/C compressor clutch engages when commanding the ECM A/C Relay output function On and Off with a scan tool.

If the A/C compressor clutch does not engage

Refer to DTC P0645, P0646, or P0647

If the A/C compressor clutch engages

  1. All OK.

Circuit/System Testing

  1. Ignition OFF, disconnect the X1 harness connector at the K33 HVAC Control Module.
  2. Install a 3 A jumper wire between the signal circuit terminal 5 and ground, A/C switch depressed.
  3. Verify the scan tool ECM A/C Request Signal parameter changes between YES and NO.

If the parameter does not change

  1. Ignition OFF, remove the jumper wire and disconnect the X2 harness connector at the K33 HVAC Control Module.
  2. Test for infinite resistance between the control circuit and ground.
  • If less than infinite resistance, repair the short to ground on the circuit.
  • If infinite resistance
  1. Test for less than 2 ohms in the control circuit end to end.
  • If 2 ohms or greater, repair the open/high resistance in the circuit.
  • If less than 2 ohms, replace the K33 HVAC Control Module.

If the parameter changes

  1. Replace the K33 HVAC Control Module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

  • HVAC Component Replacement Reference (C60)
  • Control Module References for HVAC control module replacement, programming and setup

Air conditioning compressor malfunction (C67)

Diagnostic Instructions

  • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
  • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
  • Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Circuit/System Description

The A/C compressor uses a conventional belt driven magnetic clutch to engage and mechanically turn the compressor. When the A/C switch is pressed, the HVAC control module sends an A/C request message to the ECM via serial data. If specific criteria is met, the ECM then grounds the A/C compressor clutch relay control circuit, which will switch the A/C compressor clutch relay. With the relay contacts closed, battery voltage is supplied to the permanently grounded A/C compressor clutch. The A/C compressor clutch will then be activated.

Diagnostic Aids

The following conditions must be met in order to turn on the A/C compressor:

  • Battery voltage is between 9-18 V.
  • Engine coolant temperature is less than 124ºC (255ºF).
  • Engine speed is greater than 600 RPM.
  • Engine speed is less than 5 500 RPM.
  • A/C high side pressure is between 269-2 929 kPa (39-425 PSI).
  • Throttle position is less than 100%.
  • Evaporator temperature is greater than 3ºC (38ºF).
  • ECM does not detect excessive torque load.
  • ECM does not detect insufficient idle quality.
  • The ambient temperature is above 1ºC (34ºF).
  • Blower motor must be in any other position than off.
  • A/C switch is depressed.

Reference Information

Schematic Reference

HVAC Schematics (Encore), HVAC Schematics (Encore)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - Encore

Description and Operation

Manual HVAC Description and Operation

Electrical Information Reference

  • Circuit Testing
  • Connector Repairs
  • Testing for Intermittent Conditions and Poor Connections
  • Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

NOTE: Refer to HVAC System Malfunction (C67) before performing this procedure

  1. Ignition ON, press and release the A/C Switch.
  2. Verify the scan tool HVAC A/C Switch parameter changes between Active and Inactive.

If the parameter does not change

Replace the A26 HVAC Controls.

If the parameter changes

  1. Set A/C system to coolest setting with blower ON.
  2. Press and release the A/C switch several times.
  3. Verify the scan tool ECM A/C Request Signal parameter changes between Active and Inactive.

If the parameter does not change

Replace the K33 HVAC Control Module.

If the parameter changes

  1. Verify the A/C compressor clutch engages when commanding the ECM A/C Relay output function On and Off with a scan tool.

If the A/C compressor clutch does not engage

Refer to DTC P0645, P0646, or P0647

If the A/C compressor clutch engages

  1. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

  • HVAC Component Replacement Reference (C67)
  • Control Module References for HVAC control module replacement, programming and setup

Blower motor malfunction (C41, C60)

Diagnostic Instructions

  • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
  • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
  • Diagnostic Procedure Instructions provides an overview of each diagnostic category

Diagnostic Fault Information

Diagnostic Fault Information

Circuit/System Description

The blower motor is supplied voltage any time the ignition is on via a relay controlled by the body control module.

The blower motor switch applies ground to the blower motor control circuit that corresponds to the selected blower speed. The resistors and the blower motor are in a series circuit. The following list represents the number of resistors in series with the blower motor per particular speed request:

  • Low speed, 3 resistors
  • Medium 1 speed, 2 resistors
  • Medium 2 speed, 1 resistors

When blower switch is in the Hi speed position, ground is applied directly to the blower motor through the blower switch.

Diagnostic Aids

Prior to motor replacement connect a direct independent B+ and ground to verify operation.

Inspect the motor shaft for rust or other foreign material which may prohibit proper motor operation.

If the motor operates properly please reinstall it, check for Preliminary Information or Technical Service Bulletins.

Reference Information

Schematic Reference

HVAC Schematics (Encore), HVAC Schematics (Encore)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - Encore

Description and Operation

Manual HVAC Description and Operation

Electrical Information Reference

  • Circuit Testing
  • Connector Repairs
  • Testing for Intermittent Conditions and Poor Connections
  • Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

  1. Ignition ON
  2. Verify the blower motor operates in all speed positions

If the blower motor does not operate in any speed position

Refer to Blower Motor Circuit Test

If the blower motor operates in one or more, but not all speed positions

Refer to Blower Motor Switch Circuit Test

If the blower motor is always ON

Refer to Blower Motor Always ON Circuit Test

If the blower motor operates correctly in all speed positions

  1. All OK.

Circuit/System Testing

Blower Motor Circuit Test

  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the R3 Blower Motor Resistor. It may take up to 10 min for all vehicle systems to power down.
  2. Place the blower motor switch in the high speed position.
  3. Test for less than 10 ohms between the control circuit terminal D and ground.

If 10 ohms or greater

  1. Ignition OFF, disconnect the X1 harness connector at the K33 HVAC Control Module.
  2. Test for greater than 2 ohms between the ground circuit terminal 1 and ground.
  • If less than 2 ohms, replace the K33 HVAC Control Module.
  • If greater than 2 ohms
  1. Test for less than 2 ohms in the ground circuit end to end.
  • If 2 ohms or greater, repair the open/high resistance in the circuit.
  • If less than 2 ohms, repair the open/high resistance in the ground connection.

If less than 10 ohms

  1. Ignition OFF, connect the harness connector at the R3 Blower Motor Resistor and disconnect the harness connector at the M8 Blower Motor.
  2. Test for less than 10 ohms between the control circuit terminal 1 and ground.

If 10 ohms or greater

  1. Ignition OFF, disconnect the harness connector at the R3 Blower Motor Resistor.
  2. Test for less than 2 ohms in the control circuit end to end.
  • If 2 ohms or greater, repair the open/high resistance in the circuit.
  • If less than 2 ohms, test or replace the R3 Blower Motor Resistor.

If less than 10 ohms

  1. Ignition OFF, disconnect the KR32E Blower Motor Relay.
  2. Test for less than 10 ohms between the ground circuit terminal R4-1 and ground.

If 10 ohms or greater

  1. Ignition OFF.
  2. Test for less than 2 ohms in the ground circuit end to end.
  • If 2 ohms or greater, repair the open/high resistance in the circuit.
  • If less than 2 ohms, repair the open/high resistance in the ground connection.

If less than 10 ohms

  1. Ignition ON.
  2. Verify a test lamp illuminates between the B+ circuit terminal R4-3 and ground.

If the test lamp does not illuminate and the circuit fuse is good

  1. Ignition OFF, remove the test lamp.
  2. Test for less than 2 ohms in the B+ circuit end to end.
  • If 2 ohms or greater, repair the open/high resistance in the circuit.
  • If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse.

If the test lamp does not illuminate and the circuit fuse is open

  1. Ignition OFF, remove the test lamp.
  2. Test for infinite resistance between the B+ circuit and ground.
  • If less than infinite resistance, repair the short to ground on the circuit.
  • If infinite resistance
  1. Test for infinite resistance between the M8 Blower Motor control circuit terminal 2 and ground.
  • If less than infinite resistance, repair the short to ground on the circuit.
  • If infinite resistance
  1. Test the KR32E Blower Motor Relay, refer to Component Testing.
  • If the relay tests OK, test or replace the M8 Blower Motor.
  • If the relay does not test OK, replace the KR32E Blower Motor Relay.

If the test lamp illuminates

  1. Verify a test lamp illuminates between the control circuit terminal R4-2 and the ground circuit terminal R4-1.

If the test lamp does not illuminate

Repair the open/high resistance in the control circuit.

If the test lamp illuminates

  1. Connect the harness connector at the M8 Blower Motor.
  2. Install a 40 A fused jumper wire between the B+ circuit terminal R4-3 and the control circuit terminal R4-5, ignition ON.
  3. Verify the M8 Blower Motor operates.

If the M8 Blower Motor does not operate

  1. Ignition OFF, remove the jumper wire and disconnect the harness connector at the M8 Blower Motor.
  2. Test for less than 2 ohms in the control circuit end to end.
  • If 2 ohms or greater, repair the open/high resistance in the circuit.
  • If less than 2 ohms, test or replace the M8 Blower Motor.

If the M8 Blower Motor operates

  1. Refer to Testing for Intermittent Conditions and Poor Connections .

Blower Motor Switch Circuit Test

  1. Ignition OFF, disconnect the harness connector at the R3 Blower Motor Resistor.
  2. Test for less than 10 ohms between each control circuit terminal listed below and ground with the blower switch in the appropriate position.
  • Blower speed 1 terminal E
  • Blower speed 2 terminal A
  • Blower speed 3 terminal B
  • Blower speed 4 terminal D

If 10 ohms or greater

  1. Ignition OFF, disconnect the X1 harness connector at the K33 HVAC Control Module.
  2. Test for less than 2 ohms in the control circuit end to end.
  • If 2 ohms or greater, repair the open/high resistance in the circuit.
  • If less than 2 ohms, replace the K33 HVAC Control Module.

If less than 10 ohms

  1. Test or replace the R3 Blower Motor Resistor.

Blower Motor Always ON Circuit Test

  1. Ignition OFF, disconnect the harness connector at the R3 Blower Motor Resistor.
  2. Place the blower motor switch in the OFF position.
  3. Test for infinite resistance between each control circuit terminal listed below and ground:
  • Blower speed 1 terminal E
  • Blower speed 2 terminal A
  • Blower speed 3 terminal B
  • Blower speed 4 terminal D

If less than infinite resistance

  1. Disconnect the X1 harness connector at the K33 HVAC Control Module.
  2. Test for infinite resistance between the control circuit and ground.
  • If less than infinite resistance, repair the short to ground on the circuit.
  • If infinite resistance, replace the K33 HVAC Control Module.

If infinite resistance

  1. Ignition OFF, disconnect the harness connector at the M8 blower motor.
  2. Test for infinite resistance between the control circuit terminal 1 and ground.

If less than infinite resistance

Repair the short to ground on the circuit

If infinite resistance

  1. Refer to Testing for Intermittent Conditions and Poor Connections .

Component Testing

Relay Test

  1. Ignition OFF, disconnect the KR32E Blower Motor Relay.
  2. Test for 60-180 ohms between terminals 85 and 86.

If not between 60-180 ohms

Replace the KR32E Blower Motor Relay.

If between 60-180 ohms

  1. Test for infinite resistance between the terminals listed below
  • 30 and 86
  • 30 and 87
  • 30 and 85
  • 85 and 87

If less than infinite resistance

Replace the KR32E Blower Motor Relay.

If infinite resistance

  1. Install a 3 A fused jumper wire between relay terminal 86 and 12 V. Install a jumper wire between relay terminal 85 and ground.
  2. Test for less than 2 ohms between terminals 30 and 87.

If 2 ohms or greater

Replace the KR32E Blower Motor Relay.

If less than 2 ohms

  1. All OK

Blower Switch

  1. Ignition OFF, disconnect the X1 harness connector at the K33 HVAC Control Module.
  2. Test for infinite resistance between the ground terminal 1 and each control terminal with the blower switch in the OFF position.

If less than infinite resistance

Replace the K33 HVAC Control Module.

If infinite resistance

  1. Test for less than 2 ohms between the ground terminal 1 and each control terminal with the switch in the appropriate position.

If 2 ohms or greater

Replace the K33 HVAC Control Module.

If less than 2 ohms

  1. All OK.

Blower Motor Resistor

  1. Ignition OFF, disconnect the harness connector at the R3 Blower Motor Resistor.
  2. Test for 2.7-3.3 ohms between terminal C and terminal E.

If not between 2.7-3.3 ohms

Replace the R3 Blower Motor Resistor

If between 2.7-3.3 ohms

  1. Test for 1.62-1.98 ohms between terminal C and terminal A.

If not between 1.62-1.98 ohms

Replace the R3 Blower Motor Resistor

If between 1.62-1.98 ohms

  1. Test for 0.72-0.88 ohms between terminal C and terminal B.

If not between 0.72-0.88 ohms

Replace the R3 Blower Motor Resistor.

If between 0.72-0.88 ohms

  1. Test for 0.36-0.44 ohms between terminal C and terminal D.

If not between 0.36-0.44 ohms

Replace the R3 Blower Motor Resistor.

If between 0.36-0.44 ohms

  1. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

  • HVAC Component Replacement Reference (C60), HVAC Component Replacement Reference (C41)
  • Control Module References for HVAC control module replacement, programming and setup

Actuator recalibration (C67)

HVAC Control Module Replacement

When replacing or disconnecting the HVAC control module, it will be necessary to perform a recalibration process. When installing or reconnecting the HVAC control module, be sure to perform the following: Preferred Method (with Scan Tool)

NOTE: Do not adjust any controls on the HVAC control module while the HVAC control module is self-calibrating. If interrupted, improper HVAC performance will result.

  1. Ignition OFF.
  2. Disconnect the scan tool.
  3. Install/connect the HVAC control module.
  4. Connect all previously disconnected components.
  5. Start the vehicle.
  6. With the scan tool, initiate the HVAC Actuators Learn feature of the HVAC control module Special Functions menu.
  7. Operate system and verify that no DTCs have set as current DTCs.
  8. If DTC B101E 4B is set after attempting the actuator recalibration procedure, perform the following:

  1. Verify which actuator does not have a scan tool learn status parameter status of complete.
  2. Verify the unlearned actuator is physically rotating - A common cause of DTC B101E 4B is an actuator that is electrically OK but fails to physically rotate (e.g. stripped gears).
  3. If the unlearned actuator is not physically rotating, replace the actuator, otherwise replace the HVAC control module.

Alternate Method (without Scan Tool)

NOTE: Do not adjust any controls on the HVAC control module while the HVAC control module is self-calibrating. If interrupted, improper HVAC performance will result.

  1. Clear all DTCs.
  2. Ignition OFF.
  3. Install/connect the HVAC control module.
  4. Connect all previously disconnected components.
  5. Remove the HVAC control module fuse for a minimum of 10 s.
  6. Install the HVAC control module fuse.
  7. Start the vehicle.
  8. Wait 40 s for the HVAC control module to self-calibrate.

Actuator Replacement

When replacing an HVAC actuator it will be necessary to allow the HVAC control module to perform a recalibration process. When installing an HVAC actuator be sure to perform one of the following: Preferred Method (with Scan Tool)

NOTE: Do not adjust any controls on the HVAC control module while the HVAC control module is self-calibrating. If interrupted, improper HVAC performance will result.

  1. Clear all DTCs.
  2. Ignition OFF.
  3. Install the HVAC actuator.
  4. Connect all previously disconnected components.
  5. Start the vehicle.
  6. With the scan tool, initiate the HVAC Actuators Relearn feature of the HVAC control module Special Functions menu.
  7. Operate system and verify that no DTCs have set as current DTCs.
  8. If DTC B101E 4B is set after attempting the actuator recalibration procedure, perform the following:

  1. Verify which actuator does not have a scan tool learn status parameter status of complete.
  2. Verify the unlearned actuator is physically rotating - A common cause of DTC B101E 4B is an actuator that is electrically OK but fails to physically rotate (e.g. stripped gears).
  3. If the unlearned actuator is not physically rotating, replace the actuator, otherwise replace the HVAC control module.

Alternate Method (without Scan Tool)

NOTE: Do not adjust any controls on the HVAC control module while the HVAC control module is self-calibrating. If interrupted, improper HVAC performance will result.

  1. Clear all DTCs.
  2. Ignition OFF.
  3. Install the HVAC actuator.
  4. Connect all previously disconnected components.
  5. Remove the HVAC control module fuse for a minimum of 10 s.
  6. Install the HVAC control module fuse.
  7. Start the vehicle.
  8. Wait 40 s for the HVAC control module to self-calibrate.

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