GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    â€¢ Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    â€¢ Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    â€¢  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC C0561 71: System Disabled Information Stored Invalid Serial Data Received

Circuit/System Description

The rear differential clutch control module (CCM) receives messages from other modules over GMLAN which are needed to perform all wheel drive functions.

Conditions for Running the DTC

    â€¢ The ignition is ON.
    â€¢ Ignition voltage is greater than 9.5 volts.

Conditions for Setting the DTC

The CCM receives an invalid message from the PCM, EBCM, modules over GMLAN which causes the CCM to deactivate.

Action Taken When the DTC Sets

All wheel drive indicator illuminates.

Conditions for Clearing the DTC

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

Diagnostic Aids

DTC C0561 is an indicator that the CCM receives an invalid message from the ECM, or EBCM , and does not necessarily indicate a fault is present with the CCM. This DTC should not be used as a fault indicator, but rather as a symptom to assist in the diagnosis of these other systems.

Reference Information

Schematic Reference

All-Wheel Drive Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

All-Wheel Drive Description and Operation

Electrical Information Reference

    â€¢  Circuit Testing
    â€¢  Connector Repairs
    â€¢  Testing for Intermittent Conditions and Poor Connections
    â€¢  Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Verify that no DTCs are set in the ECM or EBCM.

⇒If DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle.