Diagnostic Instructions

DTC Descriptor

DTC B0223 01: Recirculate Position Command 1 Circuit Short to Battery

DTC B0223 06: Recirculate Position Command 1 Circuit Short to Ground or Open

DTC B0233 01: Air Flow Control Circuit Short to Battery

DTC B0233 06: Air Flow Control Circuit Short to Ground or 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 Short to Ground or Open

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Stepper Motors 12 V Reference	B023A 02, B0223 06, B0233 06, B0408 06	B0223 06, B0233 06, B0408 06	--	--
Recirculation Actuator Control 1	B0223 06	B0223 06	B0223 01	1
Recirculation Actuator Control 2	B0223 06	B0223 06	B0223 01	1
Recirculation Actuator Control 3	B0223 06	B0223 06	B0223 01	1
Recirculation Actuator Control 4	B0223 06	B0223 06	B0223 01	1
Air Temperature Actuator - Left Control 1	B0408 06	B0408 06	B0408 01	2
Air Temperature Actuator - Left Control 2	B0408 06	B0408 06	B0408 01	2
Air Temperature Actuator - Left Control 3	B0408 06	B0408 06	B0408 01	2
Air Temperature Actuator - Left Control 4	B0408 06	B0408 06	B0408 01	2
Mode Actuator Control 1	B0233 06	B0233 06	B0233 01	3
Mode Actuator Control 2	B0233 06	B0233 06	B0233 01	3
Mode Actuator Control 3	B0233 06	B0233 06	B0233 01	3
Mode Actuator Control 4	B0233 06	B0233 06	B0233 01	3
1. Air Recirculation Malfunction 2. Air Temperature Malfunction 3. Air Distribution Malfunction

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 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

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

B0223, B0233 or B0408

Conditions for Clearing the DTC

The condition for setting the DTC is no longer present.

Reference Information

Schematic Reference

HVAC Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Automatic HVAC Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References 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 Recirculation Actuator.
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 Ω between the control circuit terminals listed below:

•	M46 Recirculation Actuator terminal 1 and terminal 16 (X3) at the K33 HVAC Control Module harness connector

•	M46 Recirculation Actuator terminal 2 and terminal 15 (X3) at the K33 HVAC Control Module harness connector

•	M46 Recirculation Actuator terminal 3 and terminal 17 (X3) at the K33 HVAC Control Module harness connector

•	M46 Recirculation Actuator terminal 4 and terminal 18 (X3) at the K33 HVAC Control Module harness connector

•	M46 Recirculation Actuator 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 Recirculation Actuator and verify the DTC does not reset.

⇒	If the DTC resets, replace the K33 HVAC Control Module.

Mode Actuator Malfunction

1. Ignition OFF, disconnect the X3 harness connector at the K33 HVAC Control Module and at the M37 Mode 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 Ω between the control circuit terminals listed below:

•	M37 Mode Actuator terminal 1 and terminal 2 (X3) at the K33 HVAC Control Module harness connector

•	M37 Mode Actuator terminal 2 and terminal 15 (X3) at the K33 HVAC Control Module harness connector

•	M37 Mode Actuator terminal 3 and terminal 3 (X3) at the K33 HVAC Control Module harness connector

•	M37 Mode Actuator terminal 4 and terminal 4 (X3) at the K33 HVAC Control Module harness connector

•	M37 Mode 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 Actuator and verify the DTC does not reset.

⇒	If the DTC resets, replace the K33 HVAC Control Module.

Air Temperature Actuator Malfunction

1. Ignition OFF, disconnect the X3 harness connector at the K33 HVAC Control Module and at the M6L Air Temperature 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 Ω between the control circuit terminals listed below:

•	M6L Air Temperature Actuator - Left terminal 1 and terminal 11 (X3) at the K33 HVAC Control Module harness connector

•	M6L Air Temperature Actuator - Left terminal 2 and terminal 15 (X3) at the K33 HVAC Control Module harness connector

•	M6L Air Temperature Actuator - Left terminal 3 and terminal 12 (X3) at the K33 HVAC Control Module harness connector

•	M6L Air Temperature Actuator - Left terminal 4 and terminal 13 (X3) at the K33 HVAC Control Module harness connector

•	M6L Air Temperature 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 Actuator - Left and verify the DTC does not reset.

⇒	If the DTC resets, replace the K33 HVAC Control Module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.