Antilock Brake System - Greater than/Equal to 3900 kg (8600 lb) GVW

DTC C0561

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.

* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC C0561 71

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System Disabled Information Stored Invalid Serial Data Received

DTC C0561 72

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System Disabled Information Stored Alive Counter Incorrect or not Updated

DTC C0561 74

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System Disabled Information Stored Value of Signal Protection Calculation Incorrect

DTC C0561 75

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System Disabled Information Stored Signal Above Allowable Range

Circuit/System Description

The electronic brake control module (EBCM) receives serial data messages from the body control module (BCM), engine control module (ECM), instrument panel cluster, and the transmission control module (TCM) which are needed to perform antilock brake system (ABS), vehicle stability enhancement system, electronic stability control, or traction control system 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, traction control system and electronic stability control.

Action Taken When the DTC Sets

One or more of the following actions may occur:

* The EBCM disables the ABS, traction control system and electronic stability control for the duration of the ignition cycle.

* The dynamic rear proportioning may be disabled and the Brake Warning indicator may turn ON.

* The Stability Caution indicator turns ON.

* The driver information center displays the SERVICE STAB SYS, or SERVICE TRACTION message.

* The Traction indicator turns ON.

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 [1][2]Antilock Brakes / Traction Control Systems

Connector End View Reference

Component Connector End Views Connector End Views By Name

Description and Operation

ABS Description and Operation Description and Operation

Electrical Information Reference

* Circuit Testing Circuit Testing

* Connector Repairs Connector Repairs

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Wiring Repairs Wiring Repairs

Scan Tool Reference

Control Module References Control Module References for scan tool information

Circuit/System Verification

Note:
Diagnose any other DTCs before attempting to diagnose C0561.

1. With a scan tool, view the EBCM invalid signal data in the Enhanced DTC Data.

2. Refer to appropriate module for diagnosing the invalid signal data.

3. Do not replace the EBCM due to this DTC fault.