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DTC B0223, B0233, B023A, or B0408

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 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 Control 1

B0408 06

B0408 06

B0408 01

1

Air Temperature Actuator Control 2

B0408 06

B0408 06

B0408 01

1

Air Temperature Actuator Control 3

B0408 06

B0408 06

B0408 01

1

Air Temperature Actuator Control 4

B0408 06

B0408 06

B0408 01

1

Mode Actuator Control 1

B0233 06

B0233 06

B0233 01

1

Mode Actuator Control 2

B0233 06

B0233 06

B0233 01

1

Mode Actuator Control 3

B0233 06

B0233 06

B0233 01

1

Mode Actuator Control 4

B0233 06

B0233 06

B0233 01

1

1. HVAC 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 serial data. The HVAC control module supplies a 12 V reference voltage to the stepper motors and energises 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

    • Vehicle in Service Mode.
    • 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

Connector End View Reference

Component Connector End Views

Description and Operation

Automatic 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. Vehicle OFF, disconnect the harness conector at the appropriate door actuator, vehicle in Service Mode.
  2. Connect a test lamp between the B+ circuit terminal 2 and ground.
  3. Verify the test lamp turns ON and OFF when commanding the actuator ON and OFF with a scan tool.
  4. If the test lamp is always OFF
    3.1. Vehicle OFF, disconnect the harness connector at the K33 HVAC control module.
    3.2. 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
    3.3. Test for less than 2 Ω in the control circuit end to end.
    ⇒     If 2 Ω or greater, repair the open/high resistance in the circuit.
    ⇒     If less than 2 Ω, replace the K33 HVAC control module.
    If the test lamp is always ON
    3.1. Vehicle OFF, disconnect the harness connector at the K33 HVAC control module, vehicle in Service Mode.
    3.2. 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 the test lamp turns ON and OFF
  5. Vehicle OFF, disconnect the harness connector at the actuator and disconnect the harness connectors at the K33 HVAC control module, vehicle in Service Mode.
  6. Test for less than 1 V between each actuator harness connector terminals listed below and ground.
  7. • Control Circuit - terminal 1
    • Control Circuit - terminal 3
    • Control Circuit - terminal 4
    • Control Circuit - terminal 6
    If 1 V or greater
        Repair the short to voltage on the circuit.
    ⇓   If less than 1 V
  8. Vehicle OFF.
  9. Test for infinite resistance between each actuator harness connector terminals listed below and ground.
  10. • Control Circuit - terminal 1
    • Control Circuit - terminal 3
    • Control Circuit - terminal 4
    • Control Circuit - terminal 6
    If less than infinite resistance
         Repair the short to ground on the circuit.
    ⇓   If Infinite resistance
  11. Test for less than 2 Ω between each harness connector terminal listed below end to end.
  12. Note: See schematic for the K33 HVAC control module terminal numbers.

    • HVAC Actuator - terminal 1 and HVAC control module terminal
    • HVAC Actuator - terminal 3 and HVAC control module terminal
    • HVAC Actuator - terminal 4 and HVAC control module terminal
    • HVAC Actuator - terminal 6 and HVAC control module terminal
    If 2 Ω or greater
        Repair the open/high resistance in the circuit.
    ⇓   If less than 2 Ω
  13. Replace the actuator. The DTC should not set.
  14. If the DTC sets
         Replace the K33 HVAC control module.
    ⇓   If the DTC does not set
  15. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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


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