Antilock Brake System

DTC C0561

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 C0561 71
- System Disabled Information Stored Invalid Serial Data Received

DTC C0561 72
- System Disabled Information Stored Alive Counter Incorrect or not Updated

DTC C0561 74
- System Disabled Information Stored Value of Signal Protection Calculation Incorrect




Circuit/System Description

The electronic brake control module (EBCM) receives messages from other modules over GMLAN which are needed to perform antilock brake system (ABS), vehicle stability enhancement system (VSES), or traction control system (TCS) functions.


Conditions for Running the DTC

* The ignition switch is in the ON position.
* Ignition voltage is greater than 9.5 volts.



Conditions for Setting the DTC

The EBCM receives an invalid message from another module over GMLAN which causes EBCM to deactivate ABS, VSES, TCS, etc.


Action Taken When the DTC Sets

One or more of the following actions may occur:

* The EBCM disables the ABS/TCS/VSES for the duration of the ignition cycle.
* The dynamic rear proportioning (DRP) may be disabled and the Brake Warning indicator may turn ON.
* The Stability Caution indicator turns ON.
* The driver information center (DIC) displays the SERVICE STAB SYS message.
* The DIC displays the TRACTION FAILED message.



Conditions for Clearing the DTC

* The condition for the DTC is no longer present.
* The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.



Reference Information
Schematic Reference

Antilock Brake System Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views
Description and Operation

ABS Description and Operation (With JL4) (ABS Description and Operation (With RPO JL4))ABS Description and Operation (Without JL4) (ABS Description and Operation (Without RPO JL4))
Electrical Information Reference

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

Scan Tool Reference

Control Module References for Scan Tool Information


Circuit/System Verification

1. Perform the Diagnostic System Check Vehicle. Diagnose any other DTCs before attempting to diagnosis of C0561.
2. With a Tech 2, view the Invalid Signal Data Display.
3. If no invalid signal are present, view Signal Fault Data in the Enhanced DTC Data.
4. Refer to appropriate module for diagnosing the invalid message data.
5. Do not replace the EBCM due to this DTC fault.



Repair Verification

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.