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| • | 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. |
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 | ||||
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.
| • | Vehicle in Service Mode. |
| • | The HVAC control module is ON. |
The stepper motors supply output is shorted to ground.
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.
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.
| • | The affected output will be switched off for hardware protection. |
| • | All stepper motors are deactivated. |
| • | The affected output will be switched off for hardware protection. |
| • | The affected stepper motor is deactivated. |
The condition for setting the DTC is no longer present.
Automatic HVAC Description and Operation
Control Module References for scan tool information
| ⇒ | 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 |
| • | 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 |
| • | 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 |
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 |
| ⇒ | If the DTC sets |
| Replace the K33 HVAC control module. |
| ⇓ | If the DTC does not set |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for HVAC control module replacement, programming and setup |
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