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B022A




DTC B0223, B022A, B0233, B023A, B0408, or B0418

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.

* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC B0223 01

-
Recirculate Position Command 1 Circuit Short to Battery

DTC B0223 06

-
Recirculate Position Command 1 Circuit Low Voltage/Open

DTC B022A 01

-
Recirculate Position Command 2 Circuit Short to Battery

DTC B022A 06

-
Recirculate Position Command 2 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

DTC B0418 01

-
Right Temperature Control Circuit Short to Battery

DTC B0418 06

-
Right Temperature Control Circuit Low Voltage/Open

Diagnostic Fault Information






Circuit/System Description

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

With the appropriate switches at the HVAC control, the desired air temperature flap position, air distribution flap position and air recirculation flap position can be put in. The selected values are passed to the HVAC control module via LIN-Bus. The HVAC control module supplies a 12 V reference voltage to the stepper motors and energizes the 4 stepper motor coils with a pulsed ground signal. The stepper motors put the appropriate flap into the calculated position, in order to reach the put in temperature/position.

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, B022A 01, B0233 01, B0408 01 or B0418 01

At least one control output (of four possible outputs) 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, B022A 06, B0233 06, B0408 06 or B0418 06

At least one control output (of four possible outputs) 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, B022A, B0233, B0408 or B0418

* 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 HVAC - Automatic

Connector End View Reference

Component Connector End Views Sunshade - Left (DH6)

Description and Operation

Automatic HVAC Description and Operation HVAC - Automatic

Electrical Information Reference

* Circuit Testing Circuit Testing

* Connector Repairs Connector Repairs

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Wiring Repairs Wiring Repairs

Scan Tool Reference

Control Module References Control Module References for scan tool information

Circuit/System Verification

1. Verify that DTC B023A 02 is not set.

If DTC B023A is set

Refer to Actuator Power Supply Malfunction.

If DTC B023A is not set

2. Verify that DTC B0223 01 or B0223 06 is not set.

If DTC B0223 is set

Refer to Air Recirculation Actuator Malfunction.

If DTC B0223 is not set

3. Verify that DTC B022A 01 or B022A 06 is not set.

If DTC B022A is set

Refer to Air Inlet Actuator Malfunction.

If DTC B022A is not set

4. Verify that DTC B0233 01 or B0233 06 is not set.

If DTC B0233 is set

Refer to Mode Actuator Malfunction.

If DTC B0233 is not set

5. Verify that DTC B0408 01 or B0408 06 is not set.

If DTC B0408 is set

Refer to Air Temperature Actuator - Left Malfunction.

If DTC B0408 is not set

6. Verify that DTC B0418 01 or B0418 06 is not set.

If DTC B0418 is set

Refer to Air Temperature Actuator - Right Malfunction.

If DTC B0418 is not set

7. All OK.

Circuit/System Testing

Actuator Power Supply Malfunction

1. Ignition OFF, disconnect the X3 harness connector at the K33 HVAC Control Module.

2. Test for infinite resistance between the reference voltage circuit terminal 15 X3 and ground.

If less than infinite resistance

Repair the short to ground on the circuit.

If infinite resistance

3. Replace the K33 HVAC Control Module.

Air Recirculation Actuator Malfunction

1. Ignition OFF, disconnect the X3 harness connector at the K33 HVAC Control Module and at the M46 Air Recirculation Door Actuator, ignition ON.

2. Test for less than 0.3 V between the control circuit terminal at the K33 HVAC Control Module harness connector listed below and ground:

* Terminal 16 X3

* Terminal 17 X3

* Terminal 18 X3

* Terminal 19 X3

If greater than 0.3 V

Repair the short to voltage on the circuit.

If less than 0.3 V

3. Ignition OFF.

4. Test for infinite resistance between the control circuit terminal at the K33 HVAC Control Module harness connector listed below and ground:

* Terminal 16 X3

* Terminal 17 X3

* Terminal 18 X3

* Terminal 19 X3

If less than infinite resistance

Repair the short to ground on the circuit.

If infinite resistance

5. Test for less than 5 ohms between the control circuit terminals listed below:

* M46 Air Recirculation Door Actuator terminal 1 and terminal 16 X3 at the K33 HVAC Control Module harness connector

* M46 Air Recirculation Door Actuator terminal 2 and terminal 15 X3 at the K33 HVAC Control Module harness connector

* M46 Air Recirculation Door Actuator terminal 3 and terminal 17 X3 at the K33 HVAC Control Module harness connector

* M46 Air Recirculation Door Actuator terminal 4 and terminal 18 X3 at the K33 HVAC Control Module harness connector

* M46 Air Recirculation Door Actuator terminal 6 and terminal 19 X3 at the K33 HVAC Control Module harness connector

If 5 ohms or greater

Repair the open/high resistance in the circuit.

If less than 5 ohms

6. Replace the M46 Air Recirculation Door Actuator and verify the DTC does not reset.

If DTC resets

Replace the K33 HVAC Control Module.

If DTC does not reset

7. All OK.

Air Inlet Actuator Malfunction

1. Ignition OFF, disconnect the X3 and the X4 harness connector at the K33 HVAC Control Module and at the M4 Air Inlet Door Actuator, ignition ON.

2. Test for less than 0.3 V between the control circuit terminal listed below and ground:

* Terminal 1 X4

* Terminal 2 X4

* Terminal 3 X4

* Terminal 4 X4

If greater than 0.3 V

Repair the short to voltage on the circuit.

If less than 0.3 V

3. Ignition OFF.

4. Test for infinite resistance between the control circuit terminal listed below and ground:

* Terminal 1 X4

* Terminal 2 X4

* Terminal 3 X4

* Terminal 4 X4

If less than infinite resistance

Repair the short to ground on the circuit.

If infinite resistance

5. Test for less than 5 ohms between the control circuit terminals listed below:

* M4 Air Inlet Door Actuator terminal 1 and terminal 1 X4 at the K33 HVAC Control Module harness connector

* M4 Air Inlet Door Actuator terminal 2 and terminal 15 X3 at the K33 HVAC Control Module harness connector

* M4 Air Inlet Door Actuator terminal 3 and terminal 2 X4 at the K33 HVAC Control Module harness connector

* M4 Air Inlet Door Actuator terminal 4 and terminal 3 X4 at the K33 HVAC Control Module harness connector

* M4 Air Inlet Door Actuator terminal 6 and terminal 4 X4 at the K33 HVAC Control Module harness connector

If 5 ohms or greater

Repair the open/high resistance in the circuit.

If less than 5 ohms

6. Replace the M4 Air Inlet Door Actuator and verify the DTC does not reset.

If DTC resets

Replace the K33 HVAC Control Module.

If DTC does not reset

7. All OK.

Mode Actuator Malfunction

1. Ignition OFF, disconnect the X3 harness connector at the K33 HVAC Control Module and at the M37 Mode Door Actuator, ignition ON.

2. Test for less than 0.3 V between the control circuit terminal listed below and ground:

* Terminal 2 X3

* Terminal 3 X3

* Terminal 4 X3

* Terminal 5 X3

If greater than 0.3 V

Repair the short to voltage on the circuit.

If less than 0.3 V

3. Ignition OFF.

4. Test for infinite resistance between the control circuit terminal listed below and ground:

* Terminal 2 X3

* Terminal 3 X3

* Terminal 4 X3

* Terminal 5 X3

If less than infinite resistance

Repair the short to ground on the circuit.

If infinite resistance

5. Test for less than 5 ohms between the control circuit terminals listed below:

* M37 Mode Door Actuator terminal 1 and terminal 2 X3 at the K33 HVAC Control Module harness connector

* M37 Mode Door Actuator terminal 2 and terminal 15 X3 at the K33 HVAC Control Module harness connector

* M37 Mode Door Actuator terminal 3 and terminal 3 X3 at the K33 HVAC Control Module harness connector

* M37 Mode Door Actuator terminal 4 and terminal 4 X3 at the K33 HVAC Control Module harness connector

* M37 Mode Door Actuator terminal 6 and terminal 5 X3 at the K33 HVAC Control Module harness connector

If 5 ohms or greater

Repair the open/high resistance in the circuit.

If less than 5 ohms

6. Replace the M37 Mode Door Actuator and verify the DTC does not reset.

If DTC resets

Replace the K33 HVAC Control Module.

If DTC does not reset

7. All OK.

Air Temperature Actuator - Left Malfunction

1. Ignition OFF, disconnect the X3 harness connector at the K33 HVAC Control Module and at the M6L Air Temperature Door Actuator - Left, ignition ON.

2. Test for less than 0.3 V between the control circuit terminal listed below and ground:

* Terminal 11 X3

* Terminal 12 X3

* Terminal 13 X3

* Terminal 14 X3

If greater than 0.3 V

Repair the short to voltage on the circuit.

If less than 0.3 V

3. Ignition OFF.

4. Test for infinite resistance between the control circuit terminal listed below and ground:

* Terminal 11 X3

* Terminal 12 X3

* Terminal 13 X3

* Terminal 14 X3

If less than infinite resistance

Repair the short to ground on the circuit.

If infinite resistance

5. Test for less than 5 ohms between the control circuit terminals listed below:

* M6L Air Temperature Door Actuator - Left terminal 1 and terminal 11 X3 at the K33 HVAC Control Module harness connector

* M6L Air Temperature Door Actuator - Left terminal 2 and terminal 15 X3 at the K33 HVAC Control Module harness connector

* M6L Air Temperature Door Actuator - Left terminal 3 and terminal 12 X3 at the K33 HVAC Control Module harness connector

* M6L Air Temperature Door Actuator - Left terminal 4 and terminal 13 X3 at the K33 HVAC Control Module harness connector

* M6L Air Temperature Door Actuator - Left terminal 6 and terminal 14 X3 at the K33 HVAC Control Module harness connector

If 5 ohms or greater

Repair the open/high resistance in the circuit.

If less than 5 ohms

6. Replace the M6L Air Temperature Door Actuator - Left and verify the DTC does not reset.

If DTC resets

Replace the K33 HVAC Control Module.

If DTC does not reset

7. All OK.

Air Temperature Actuator - Right Malfunction

1. Ignition OFF, disconnect the X3 and the X4 harness connector at the K33 HVAC Control Module and at the M6R Air Temperature Door Actuator - Right, ignition ON.

2. Test for less than 0.3 V between the control circuit terminal listed below and ground:

* Terminal 5 X4

* Terminal 6 X4

* Terminal 7 X4

* Terminal 8 X4

If greater than 0.3 V

Repair the short to voltage on the circuit.

If less than 0.3 V

3. Ignition OFF.

4. Test for infinite resistance between the control circuit terminal listed below and ground:

* Terminal 5 X4

* Terminal 6 X4

* Terminal 7 X4

* Terminal 8 X4

If less than infinite resistance

Repair the short to ground on the circuit.

If infinite resistance

5. Test for less than 5 ohms between the control circuit terminals listed below:

* M6R Air Temperature Door Actuator - Right terminal 1 and terminal 5 X4 at the K33 HVAC Control Module harness connector

* M6R Air Temperature Door Actuator - Right terminal 2 and terminal 15 X3 at the K33 HVAC Control Module harness connector

* M6R Air Temperature Door Actuator - Right terminal 3 and terminal 6 X4 at the K33 HVAC Control Module harness connector

* M6R Air Temperature Door Actuator - Right terminal 4 and terminal 7 X4 at the K33 HVAC Control Module harness connector

* M6R Air Temperature Door Actuator - Right terminal 6 and terminal 8 X4 at the K33 HVAC Control Module harness connector

If 5 ohms or greater

Repair the open/high resistance in the circuit.

If less than 5 ohms

6. Replace the M6R Air Temperature Door Actuator - Right and verify the DTC does not reset.

If DTC resets

Replace the K33 HVAC Control Module.

If DTC does not reset

7. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.

* Temperature Valve Actuator Replacement - Left Side Temperature Valve Actuator Replacement - Left Side

* Temperature Valve Actuator Replacement - Right Side Temperature Valve Actuator Replacement - Right Side

* Mode Control Cam Actuator Replacement Mode Control Cam Actuator Replacement

* Air Inlet Valve Actuator Replacement Air Inlet Valve Actuator Replacement

* Control Module References Control Module References for HVAC control module replacement, programming and setup