Less Than 3900 KG (8600 Lb) GVW

DTC C0561

Diagnostic Instructions

- Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure Component Tests and General Diagnostics.
- Review Strategy Based Diagnosis for an overview of the diagnostic approach Component Tests and General Diagnostics.
- Diagnostic Procedure Instructions provides an overview of each diagnostic category Component Tests and General Diagnostics.

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 clears the history DTC when a current DTC is not detected in 40 consecutive drive cycles.

Note: During normal diagnostic and/or repair verification technicians may find that the ABS, Traction Control and/or Stabilitrak indicators may be ON with NO DTCs displayed by the EBCM. Do not replace the EBCM for this condition.

If the ABS, Traction Control and/or Stabilitrak telltales are ON with no DTCs set, perform the following steps:

1. Remove the key from the ignition, open and close the driver's door to turn off retained accessory power (RAP), and wait 60 seconds.
2. Ignition ON, if the ABS, Traction Control and/or Stabilitrak telltales are still illuminated, operate the vehicle at speeds greater than 15 km/h (10 mph) to complete the self test. The EBCM should request all telltale indicators to turn OFF.
3. If the telltales remain ON with no DTCs set after the drive cycle, disconnect the battery for at least 60 seconds then reconnect the battery.
4. Operate the vehicle at speeds greater than 40 km/h (25 mph), the EBCM should request all telltale indicators to turn OFF.

Reference Information

Schematic Reference

Antilock Brake System Schematics Electrical Diagrams

Connector End View Reference

Component Connector End Views Diagrams

Description and Operation

ABS 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 Reference

Control Module References for Scan Tool Information Scan Tool Testing and Procedures

Circuit/System Verification
Note: Diagnose any other DTCs before attempting to diagnose C0561.

With a scan tool, view the EBCM Signal Data Display.
If no invalid signal are present, view Invalid Signal Data in the Enhanced DTC Data.
Refer to appropriate module for diagnosing the invalid signal data.
Do not replace the EBCM due to this DTC fault.