Air Temperature Malfunction
| Air Temperature Malfunction | 
| 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. | |
| Diagnostic Fault Information | 
| Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance | 
| Stepper Motors 12V Reference | B023A 02, B0223 06, B022A 06, B0233 06, B0408 06, B0418 06 | B0223 06, B022A 06, B0233 06, B0408 06, B0418 06 | - | - | 
| Air Temperature Actuator - Left Control 1 | B0408 06 | B0408 06 | B0408 01 | 1 | 
| Air Temperature Actuator - Left Control 2 | B0408 06 | B0408 06 | B0408 01 | 1 | 
| Air Temperature Actuator - Left Control 3 | B0408 06 | B0408 06 | B0408 01 | 1 | 
| Air Temperature Actuator - Left Control 4 | B0408 06 | B0408 06 | B0408 01 | 1 | 
| Air Temperature Actuator - Right Control 1 | B0418 06 | B0418 06 | B0418 01 | 1 | 
| Air Temperature Actuator - Right Control 2 | B0418 06 | B0418 06 | B0418 01 | 1 | 
| Air Temperature Actuator - Right Control 3 | B0418 06 | B0418 06 | B0418 01 | 1 | 
| Air Temperature Actuator - Right Control 4 | B0418 06 | B0418 06 | B0418 01 | 1 | 
| 1. Air Temperature Malfunction | ||||
| Circuit/System Description | 
With the temperature switches at the Radio/HVAC control, the wished air temperature flap position can be put in. The selected values are sent to the HVAC control module via 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 mixed air flaps into the calculated position, in order to reach the put in temperature.
| Diagnostic Aids | 
Check the following mechanical fault sources:
| • | Air distribution box | |
| • | Air distribution hoses/air distribution ducts | |
| 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 Verification | 
| 1. | Ignition ON, measure actual inside air temperature using a thermometer. Compare this value to the scan tool Passenger Compartment Air Temperature parameter. The measured temperature should be within 5°C (9°F) difference of parameter value. | |
| 2. | If not within the specified range, refer to
        
         DTC B0163, B0183, or B1405
        
        . | |
| 3. | Measure actual temperature using a thermometer at each of the duct temperature sensors. Compare this value to the appropriate scan tool Duct Actual parameter. The measured temperature should be within 5°C (9°F) difference of appropriate Duct Actual parameter value. | |
| 4. | If not within the specified range, refer to
        
         DTC B0173, B0178, B0509, B0514, B0519, B3583, or B3933
        
        . | |
| 5. | Measure actual evaporator temperature using a thermometer. Compare this value to the scan tool A/C Evaporator Temperature Sensor parameter. The measured temperature should be within 5°C (9°F) difference of parameter value. | |
| 6. | If not within the specified range, refer to
        
         DTC B0173, B0178, B0509, B0514, B0519, B3583, or B3933
        
        . | |
| 7. | Observe the scan tool Sunload parameter. The reading should be between 50-1 150 W/m
        
         2
        
        and change with sunlight intensity. | |
| 8. | If not within the specified range or not change, refer to
        
         DTC B0163, B0183, or B1405
        
        . | |
| 9. | Engine is running, activate and deactivate the A/C switch. Verify the A/C compressor can be activated and deactivated. | |
| 10. | If the A/C compressor cannot be activated or deactivated, refer to
        
         Air Conditioning Compressor Malfunction (LAU, LBR, LBS, LDK, or LHU)
        
        or
        
         Air Conditioning Compressor Malfunction (LLU)
        
        . | |
| 11. | Verify the engine reaches its operating temperature. | |
| Circuit/System Testing | 
| 1. | Ignition ON, turn the left temperature knob in all positions. Verify the scan tool Left Temperature Knob Position parameter. The reading should correspond to the selected temperature. | |
| 2. | If not the specified value, replace the A20 Radio/HVAC Controls. | |
| 3. | Ignition ON, turn the right temperature knob in all positions. Verify the scan tool Right Temperature Knob Position parameter. The reading should correspond to the selected temperature. | |
| 4. | If not the specified value, replace the A20 Radio/HVAC Controls. | |
| 5. | Press and release the AUTO Switch. Verify the scan tool Auto HVAC Button parameter changes between Active and Inactive. | |
| 6. | If not the specified value, replace the A20 Radio/HVAC Controls. | |
| 7. | Press and release the ZONE Switch. Verify the scan tool MULTI-ZONE Switch parameter changes between Active and Inactive. | |
| 8. | If not the specified value, replace the A20 Radio/HVAC Controls. | |
| 9. | Verify the M6L Air Temperature Door Actuator - Left can be put into all positions. | |
| 10. | If the M6L Air Temperature Door Actuator - Left cannot be put into all positions, replace the M6L Air Temperature Door Actuator - Left and verify the M6L Air Temperature Door Actuator - Left can be put into all positions. If the M6L Air Temperature Door Actuator - Left cannot be put into all positions, replace the K33 HVAC Control Module. | |
| 11. | If all circuits test normal, replace the M6R Air Temperature Door Actuator - Right and verify the M6R Air Temperature Door Actuator - Right can be put into all positions. If the M6R Air Temperature Door Actuator - Right cannot be put into all positions, replace the K33 HVAC Control Module. | |
| Repair Instructions | 
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Temperature Valve Actuator Replacement - Left Side (Right Hand Drive)
        
        
         Temperature Valve Actuator Replacement - Left Side (Left Hand Drive) | |
| • | Temperature Valve Actuator Replacement - Right Side (Left Hand Drive) | |
| • | Instrument Panel Lower Center Trim Panel Replacement | |
| • | Control Module References
        
        for HVAC control module replacement, setup, and programming | |

 
		