HVAC - Manual
DTC B0223, B0233, B023A, or B0408
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 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
Circuit/System Description
Stepper motors are used for temperature regulation, air distribution control and recirculation flap control.
With the appropriate switches at the HVAC control, the desired air temperature flap position, air distribution flap position and recirculation flap position can be put in. The selected values are passed to the HVAC control module via the local interconnect network (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, B0233 01 or B0408 01
At least one control output (of 4 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, B0233 06 or B0408 06
At least one control output (of 4 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, B0233 or B0408
* 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 - Manual)
Connector End View Reference
Component Connector End Views (Connector End Views By Name)
Description and Operation
Manual HVAC Description and Operation (HVAC - Manual)
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 (Programming and Relearning) for scan tool information
Circuit/System Verification
1. Verify that DTC B023A 02 is not present.
• If DTC is present, refer to Actuator Power Supply Malfunction.
2. Verify that DTC B0223 01 or B0223 06 is not present.
• If DTC is present, refer to Recirculation Actuator Malfunction.
3. Verify that DTC B0233 01 or B0233 06 is not present.
• If DTC is present, refer to Mode Actuator Malfunction.
4. Verify that DTC B0408 01 or B0408 06 is not present.
• If DTC is present, refer to Air Temperature Actuator Malfunction.
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 the specified value, test the reference voltage circuit for a short to ground.
3. If all circuits test normal, test or replace the K33 HVAC Control Module.
Recirculation Actuator Malfunction
1. Ignition OFF, disconnect the X3 harness connector at the K33 HVAC Control Module and at the M46 Air Recirculation Door Motor.
2. Ignition ON, 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 the specified value, test the control circuit for a short to voltage.
3. Ignition OFF, 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 the specified value, test the control circuit for a short to ground.
4. Test for less than 5 ohm between the control circuit terminals listed below:
* M46 Air Recirculation Door Motor terminal 1 and terminal 16 X3 at the K33 HVAC Control Module harness connector
* M46 Air Recirculation Door Motor terminal 2 and terminal 15 X3 at the K33 HVAC Control Module harness connector
* M46 Air Recirculation Door Motor terminal 3 and terminal 17 X3 at the K33 HVAC Control Module harness connector
* M46 Air Recirculation Door Motor terminal 4 and terminal 18 X3 at the K33 HVAC Control Module harness connector
* M46 Air Recirculation Door Motor terminal 6 and terminal 19 X3 at the K33 HVAC Control Module harness connector
• If greater than the specified value, test the control circuit for an open/high resistance.
5. If all circuits test normal, replace the M46 Air Recirculation Door Motor.
Mode Actuator Malfunction
1. Ignition OFF, disconnect the X3 harness connector at the K33 HVAC Control Module and at the M37 Mode Door Actuator.
2. Ignition ON, 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 the specified value, test the control circuit for a short to voltage.
3. Ignition OFF, 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 the specified value, test the control circuit for a short to ground.
4. Test for less than 5 ohm 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 greater than the specified value, test the control circuit for an open/high resistance.
5. If all circuits test normal, replace the M37 Mode Door Actuator.
Air Temperature Actuator Malfunction
1. Ignition OFF, disconnect the X3 harness connector at the K33 HVAC Control Module and at the M6L Air Temperature Door Actuator - Left.
2. Ignition ON, 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 the specified value, test the control circuit for a short to voltage.
3. Ignition OFF, 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 the specified value, test the control circuit for a short to ground.
4. Test for less than 5 ohm 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 greater than the specified value, test the control circuit for an open/high resistance.
5. If all circuits test normal, replace the M6L Air Temperature Door Actuator - Left.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Air Inlet Valve Actuator Replacement (Air Inlet Valve Actuator Replacement)
* Temperature Valve Actuator Replacement (Temperature Valve Actuator Replacement)
* Mode Control Cam Actuator Replacement (Mode Control Cam Actuator Replacement)
* Control Module References (Programming and Relearning)