PRE-RELEASE
Air Delivery Improper - Auxiliary
| Air Delivery Improper - Auxiliary |
| 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 12 V Reference
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B023A 02, B0233 06, B022A 06, B0223 06, B0408 06, B0418 06, B0428 06, B3531 06
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B0233 06, B022A 06, B0223 06, B0408 06, B0418 06, B0428 06, B3531 06
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-
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Rear Mode Actuator Control 1
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B3531 06
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B3531 06
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B3531 01
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1
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Rear Mode Actuator Control 2
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B3531 06
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B3531 06
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B3531 01
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1
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Rear Mode Actuator Control 3
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B3531 06
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B3531 06
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B3531 01
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1
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Rear Mode Actuator Control 4
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B3531 06
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B3531 06
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B3531 01
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1
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1. Air Delivery Improper - Auxiliary
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| Circuit/System Description |
With the MODE switch at the Radio/HVAC control - auxiliary, 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 rear mode switch. Verify the scan tool Auxiliary Mode Switch Position parameter. The reading should correspond to the selected mode.
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| 2. |
If not the specified value, replace the A21 Radio/HVAC Controls - Auxiliary.
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| 3. |
If all circuits test normal, replace the M37B Mode Door Actuator - Auxiliary and verify the M37B Mode Door Actuator - Auxiliary can be put into all positions. If the M37B Mode Door Actuator - Auxiliary 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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Heater and Air Conditioning and Radio Control Module Replacement
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Auxiliary Mode Valve Actuator Replacement
for auxiliary mode valve actuator replacement
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Control Module References
for HVAC control module replacement, setup, and programming
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