C0550

DTC C0550

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.

DTC Descriptors
DTC C0550 00
- EEPROM Checksum Mismatch

DTC C0550 39
- EEPROM Checksum Mismatch

Circuit/System Description

When the ignition is turned ON, the microprocessor runs a diagnostic program to detect an internal fault when power up is commanded. If an internal malfunction is detected, the control module will store a DTC C0550 in its memory.

Conditions for Running the DTC

The microprocessor runs a diagnostic program to detect an internal fault when power up is commanded. The only requirements are voltage and ground.

Conditions for Setting the DTC

* The control module detects an internal write malfunction.
* The control module detects an internal checksum malfunction.

Action Taken When the DTC Sets

If equipped, the following module specific actions may occur:

* The antilock brake system (ABS) indicator turns ON.
* The BRAKE warning indicator turns ON.
* The electronic brake control module (EBCM) disables the ABS/dynamic rear proportion (DRP)/traction control system (TCS).
* The driver information center (DIC) displays the power steering warning message No Steering Assist.
* The TCS indicator turns ON.

Conditions for Clearing the DTC

* A current DTC clears when the malfunction is no longer present.
* A history DTC clears when the control module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.

Reference Information
Schematic Reference

Data Communication Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Data Link Communications Description and Operation (Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool References

Control Module References (Programming and Relearning)for Scan Tool Information

Circuit/System Verification

Verify that DTC C0550 is not set.

If the DTC is set, perform the learn procedure on the control module. If the DTC resets, replace the applicable control module.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

Control Module References (Programming and Relearning)for control module replacement, setup, and programming