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Diagnostic Test

WARNING: This page is about a different car, the 2006 Dodge Magnum, 2006 Dodge Charger, and 2006 Chrysler 300. However, it is still accessible from the selected car via links, so may be relevant.
  1. 1)  CHECK (C105) HVAC MUX CONTROL CIRCUIT VOLTAGE AT A/C HEATER CONTROL C1 HARNESS CONNECTOR 
    Fig 1: Measuring Voltage Of HVAC MUX Control Circuit
    GC0028220Courtesy of DAIMLERCHRYSLER CORP.

    Turn the ignition off.

    Disconnect the A/C Heater Control C1 harness connector.

    Turn the ignition on.

    Measure the voltage of the (C105) HVAC MUX Control circuit.

    Is the voltage below 4.8 volts? 

    Yes  

    1. Go To step  2).

    No 

    1. Replace the A/C Heater Control in accordance with the Service Information.
    2. Perform BODY VERIFICATION TEST - VER 1. (Refer to ELECTRICAL/ELECTRONIC CONTROL MODULES/FRONT CONTROL MODULE - DIAGNOSIS AND TESTING) .
  2. 2)  CHECK (C105) HVAC MUX CONTROL CIRCUIT FOR A SHORT TO GROUND 
    Fig 2: Checking A/C Switch Sense Circuit For Short To Ground
    GC0028221Courtesy of DAIMLERCHRYSLER CORP.

    Turn the ignition off.

    Disconnect the Instrument Cluster C2 harness connector.

    Measure the resistance of the (C105) HVAC MUX Control circuit between ground and the A/C Heater Control C1 harness connector.

    Is the resistance below 10K ohms? 

    Yes 

    1. Repair the (C105) HVAC MUX Control circuit for a short to ground.
    2. Perform BODY VERIFICATION TEST - VER 1. (Refer to ELECTRICAL/ELECTRONIC CONTROL MODULES/FRONT CONTROL MODULE - DIAGNOSIS AND TESTING) .

    No 

    1. Go To step  3).
  3. 3)  CHECK (C105) HVAC MUX CONTROL CIRCUIT FOR AN OPEN 
    Fig 3: Checking HVAC MUX Control Circuit For Open
    GC0013892Courtesy of DAIMLERCHRYSLER CORP.

    Measure the resistance of the (C105) HVAC MUX Control circuit between the A/C Heater Control C1 harness connector and the Instrument Cluster C2 harness connector.

    Is the resistance below 5.0 ohms? 

    Yes 

    1. Replace the Instrument Cluster (CCN) in accordance with the Service Information.
    2. Perform BODY VERIFICATION TEST - VER 1. (Refer to ELECTRICAL/ELECTRONIC CONTROL MODULES/FRONT CONTROL MODULE - DIAGNOSIS AND TESTING) .

    No 

    1. Repair the (C105) HVAC MUX Control circuit for an open.
    2. Perform BODY VERIFICATION TEST - VER 1. (Refer to ELECTRICAL/ELECTRONIC CONTROL MODULES/FRONT CONTROL MODULE - DIAGNOSIS AND TESTING) .
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