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 C0550 36: Electronic Control Unit Malfunction EEPROM Failure

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

EEPROM Failure

Internal Electronic Failure

Electronic Control Unit Malfunction

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C0550 36

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Circuit/System Description

This DTC indicates an EEPROM failure where diagnostic data is stored.

Conditions for Running the DTC

    • The ignition is ON.
    • System voltage is 9-16 volts.

Conditions for Setting the DTC

The EEPROM has failed and diagnostic data as well as other assorted data can not be stored.

Action Taken When the DTC Sets

    • Activation is still disabled until the conditions for setting the DTC are no longer present.
    • The SERVICE AWD indicator remains illuminated for the remainder of the current ignition cycle.

Conditions for Clearing the DTC

    • The transfer case shift control module clears the DTC if the conditions for setting the DTC are not currently present.
    • A history DTC clears after 40 consecutive warm up cycles without a fault present.
    • All DTCs can be cleared using a scan tool.
    • Clearing DTCs will also clear failure records.

Diagnostic Aids

    • Check failure records for further information on the conditions present when this DTC set.
    • It is sometimes possible to set this DTC falsely due to low voltage. Attempt to clear this DTC and retest.

Reference Information

Schematic Reference

All-Wheel Drive Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

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

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information.

Circuit/System Testing

If this DTC sets attempt to clear the DTC and Retest.

If the DTC is cleared, but then resets then replace the transfer case control module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for TCSCM replacement, setup, and programming.