GM Service Manual Online
For 1990-2009 cars only

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.

DTC Descriptor

DTC C0394 06:  Rear Differential Temperature Sensor Circuit

Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

High Clutch Temperature Sensor Circuit

C0394 06

C0394 06

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Low Clutch Temperature Sensor Circuit

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C0394 06

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Circuit/System Description

The Rear Differential Clutch Control Module (RDCCM) provides a power and ground circuits to the temperature sensor. When the temperature of the module is determined to be beyond its limits, the RDCCM will temporarily disable the rear drive system.

Conditions for Running the DTC

    • The ignition is ON.
    • Ignition voltage is greater than 9 volts.

Conditions for Setting the DTC

An open or short to ground is detected on the temperature sensor circuits.

Action Taken When the DTC Sets

One or more of the following actions may occur:

    • All Wheel Drive Off (AWD Disabled) DIC message.
    • Service All Wheel Drive (Service AWD) DIC message.

Conditions for Clearing the DTC

    • The condition for the DTC is no longer present.
    • The DTC is not detected in 40 consecutive drive cycles.

Reference Information

Schematic Reference

All-Wheel Drive Schematics

Connector End View Reference

Transfer Case Control Connector End Views

Description and Operation

All-Wheel Drive Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Scan Tool Data List for Scan Tool Information

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector C1 at the rear differential clutch control module .
  2. Ignition ON, verify a test lamp does not illuminate between the following circuit terminals and ground:
  3. • Signal circuit terminal 4
    • Low reference circuit terminal 2
         ⇒If the test lamp illuminates, test the appropriate circuit for a short to voltage.
  4. Ignition OFF, test for infinite resistance between the following circuit terminals and ground:
  5. • Signal circuit terminal 4
    • Low reference circuit terminal 2
         ⇒If less than the specified value, test the appropriate circuit for a short to ground. If the circuit tests normal, replace the rear differential.
  6. Test for 310 to 113K ohms of resistance between the signal circuit terminal 4 and the low reference circuit terminal 2.
  7. If less than the specified range, test both circuits for an open/high resistance. If the circuit tests normal, replace the rear differential.
    If greater than the specified range, test both circuits for an open/high resistance. If the circuit tests normal, replace the rear differential.
  8. If all circuits test normal, replace the RDCCM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for RDCCM replacement, setup, and programming

The temperature sensor and coil internal in the differential, and is replace as an assembly. Refer to Differential Replacement