Antilock Brake System

DTC C0561

Diagnostic Instructions

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

DTC Descriptor

DTC C0561 71

System Disabled Information Stored Invalid Serial Data Received

Diagnostic Fault Information





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.

Circuit/System Verification

1. Perform Diagnostic System Check - Vehicle. Initial Inspection and Diagnostic Overview
^ Diagnose any other Vehicle DTCs before attempting diagnosis of C0561.

2. With Tech 2, view "Signals" Data Display list under EBCM.
3. Refer to appropriate module for diagnosing any "invalid" signals.
4. If no invalid signals are present, view "Signal Fault" data in "Enhanced DTC Data".
5. Refer to appropriate module for diagnosing that invalid message data.
6. Do not replace the EBCM due to this DTC fault.

Repair Verification

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