PRE-RELEASE
Air Delivery Improper
| Air Delivery Improper |
| 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, B0233 06, B022A 06, B0223 06, B0408 06, B0418 06
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B0233 06, B022A 06, B0223 06, B0408 06, B0418 06
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Mode Actuator Control 1
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B0233 06
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B0233 06
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B0233 01
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1
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Mode Actuator Control 2
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B0233 06
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B0233 06
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B0233 01
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1
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Mode Actuator Control 3
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B0233 06
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B0233 06
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B0233 01
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1
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Mode Actuator Control 4
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B0233 06
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B0233 06
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B0233 01
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1
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1. Air Distribution Malfunction
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| Circuit/System Description |
With the defrost switch, air to foot well switch, air to windscreen switch and the air to head area switch at the HVAC control, the wished air distribution flap position can be put in. The selected value is sent to the HVAC control module via the LIN-Bus. The HVAC control module supplies a 12 V reference voltage to the stepper motor and energizes the 4 stepper motor coils with a pulsed ground signal. The stepper motor puts the air distribution flap into the selected position.
| 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 Testing |
| 1. |
Ignition ON, press and release the switch for air distribution to head. Verify the scan tool Front Defrost Switch parameter changes between Active and Inactive.
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| 2. |
If not the specified value, replace the A20 Radio/HVAC Controls.
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Press and release the switch for air distribution to face. Verify the scan tool Instrument Panel Vents switch parameter changes between Active and Inactive.
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| 4. |
If not the specified value, replace the A20 Radio/HVAC Controls.
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Press and release the switch for air distribution to floor. Verify the scan tool Floor Mode Switch parameter changes between Active and Inactive.
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If not the specified value, replace the A20 Radio/HVAC Controls.
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Press and release the defrost switch. Verify the scan tool Enhanced Defrost Switch parameter changes between Active and Inactive.
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If not the specified value, replace the A20 Radio/HVAC Controls.
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| 9. |
If all circuits test normal, replace the M37 Mode Door Actuator and verify the M37 Mode Door Actuator can be put into all positions. If the M37 Mode Door Actuator 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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Mode Control Cam Actuator Replacement (Right Hand Drive)
Mode Control Cam Actuator Replacement (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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