B0408
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 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
Circuit/System Description
Stepper motors are used for temperature regulation, air distribution control and recirculation door control.
The actuator stepper motors are controlled with the switches on the Radio/HVAC control, air temperature, mode and recirculation door position can be selected. The selected values are passed to the HVAC control module via the serial data. 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 move the appropriate doors into the calculated positions, in order to reach the desired 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 circuit 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 circuit 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 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 Electrical Diagrams
Connector End View Reference
Component Connector End Views Fuel Pump and Level Sensor Assembly
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 Control Module References for scan tool information
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the appropriate door actuator, ignition ON.
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.
• If the test lamp is always OFF
1. Ignition OFF, 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
3. 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 test lamp is always ON
1. Ignition OFF, 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, replace the K33 HVAC control module.
• If the test lamp turns ON and OFF
4. Ignition OFF, disconnect the harness connector at the actuator and disconnect the harness connectors at the K33 HVAC control module, ignition ON.
5. Test for less than 1 V between each actuator harness connector terminals listed below and ground.
* 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
6. Ignition OFF.
7. Test for infinite resistance between each actuator harness connector terminals listed below and ground.
* 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
8. Test for less than 2 ohms between each harness connector terminal listed below end to end.
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 ohms or greater
Repair the open/high resistance in the circuit.
• If less than 2 ohms
9. Replace the actuator. The DTC should not set.
• If the DTC sets
Replace the K33 HVAC control module.
• If the DTC does not set
10. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* HVAC Component Replacement Reference Removal and Replacement
* Control Module References Control Module References for HVAC control module replacement, setup, and programming