PRE-RELEASE
Air Temperature Malfunction
| Air Temperature Malfunction |
| Diagnostic Instructions |
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Perform the
Diagnostic System Check - Vehicle
prior to using this diagnostic procedure.
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Review
Strategy Based Diagnosis
for an overview of the diagnostic approach.
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Diagnostic Procedure Instructions
provides an overview of each diagnostic category.
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| Diagnostic Fault Information |
| Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
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Stepper Motors 12V Reference
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B023A 02, B0223 06, B022A 06, B0233 06, B0408 06, B0418 06
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B0223 06, B022A 06, B0233 06, B0408 06, B0418 06
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Air Temperature Actuator - Left Control 1
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B0408 06
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B0408 06
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B0408 01
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1
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Air Temperature Actuator - Left Control 2
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B0408 06
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B0408 06
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B0408 01
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1
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Air Temperature Actuator - Left Control 3
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B0408 06
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B0408 06
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B0408 01
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1
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Air Temperature Actuator - Left Control 4
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B0408 06
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B0408 06
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B0408 01
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1
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Air Temperature Actuator - Right Control 1
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B0418 06
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B0418 06
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B0418 01
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1
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Air Temperature Actuator - Right Control 2
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B0418 06
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B0418 06
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B0418 01
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1
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Air Temperature Actuator - Right Control 3
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B0418 06
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B0418 06
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B0418 01
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1
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Air Temperature Actuator - Right Control 4
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B0418 06
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B0418 06
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B0418 01
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1
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1. Air Temperature Malfunction
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| 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:
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Air distribution box
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Air distribution hoses/air distribution ducts
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| 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
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Circuit Testing
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Connector Repairs
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Testing for Intermittent Conditions and Poor Connections
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Wiring Repairs
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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.
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| 2. |
If not within the specified range, refer to
DTC B0163, B0183, or B1405
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| 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.
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| 4. |
If not within the specified range, refer to
DTC B0173, B0178, B0509, B0514, B0519, B3583, or B3933
.
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| 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.
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| 6. |
If not within the specified range, refer to
DTC B0173, B0178, B0509, B0514, B0519, B3583, or B3933
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| 7. |
Observe the scan tool Sunload parameter. The reading should be between 50-1 150 W/m
2
and change with sunlight intensity.
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| 8. |
If not within the specified range or not change, refer to
DTC B0163, B0183, or B1405
.
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| 9. |
Engine is running, activate and deactivate the A/C switch. Verify the A/C compressor can be activated and deactivated.
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| 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)
.
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| 11. |
Verify the engine reaches its operating temperature.
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| 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.
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| 2. |
If not the specified value, replace the A20 Radio/HVAC Controls.
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| 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.
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| 4. |
If not the specified value, replace the A20 Radio/HVAC Controls.
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| 5. |
Press and release the AUTO Switch. Verify the scan tool Auto HVAC Button parameter changes between Active and Inactive.
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| 6. |
If not the specified value, replace the A20 Radio/HVAC Controls.
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| 7. |
Press and release the ZONE Switch. Verify the scan tool MULTI-ZONE Switch parameter changes between Active and Inactive.
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| 8. |
If not the specified value, replace the A20 Radio/HVAC Controls.
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| 9. |
Verify the M6L Air Temperature Door Actuator - Left can be put into all positions.
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| 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.
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| 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.
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| Repair Instructions |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
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Temperature Valve Actuator Replacement - Left Side (Right Hand Drive)
Temperature Valve Actuator Replacement - Left Side (Left Hand Drive)
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Temperature Valve Actuator Replacement - Right Side (Left Hand Drive)
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Instrument Panel Lower Center Trim Panel Replacement
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Control Module References
for HVAC control module replacement, setup, and programming
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