Antilock Brake System - Non-Hybrid 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
- 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
DTC C0561 75
- System Disabled Information Stored Signal Above Allowable Range
Diagnostic Fault Information
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 detects a short to ground on the accessory switch signal circuit.
* 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
* The Stability/Traction indicator lamp turns ON.
* The driver information center displays the TRACTION OFF, and STABILITRAK OFF messages.
* The EBCM disables the traction control system and electronic stability control for the duration of the ignition cycle.
Conditions for Clearing the DTC
* The condition for the DTC is no longer present.
* The history DTC will clear after 40 consecutive fault-free ignition cycles have occurred.
Reference Information
Schematic Reference
Antilock Brake System Schematics [1][2]Antilock Brakes / Traction Control Systems
Connector End View Reference
Component Connector End Views 1-2 Shift Solenoid (SS) Valve (M30)
Description and Operation
ABS Description and Operation (Without JL4) Description and OperationABS Description and Operation (With JL4) 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: Do not replace the EBCM due to this DTC fault. Diagnose all other DTCs before attempting to diagnose C0561.
1. Verify that no other DTCs are set except for C0561.
• If any other DTCs are set
Refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle.
• If no other DTCs are set
2. Ignition ON.
3. Verify the scan tool BCM Traction Control Switch parameter changes between Active and Inactive while pressing and releasing the traction control switch.
• If the parameter does not change
Refer to Circuit/System Testing.
• If the parameter changes
4. Verify the traction/stability control indicator turns ON and OFF when commanding the Instrument Panel Cluster, Lamp Test ON and OFF with a scan tool.
• If the indicator does not turn ON and OFF
Replace the IPC.
• If the indicator turns ON and OFF
5. All OK.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the traction control switch or accessory switch.
2. Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 10 ohms between the ground circuit terminal 3 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify the scan tool Traction Control Switch parameter is Inactive.
• If not the specified value, test the signal circuit terminal 1 for a short to ground. If the circuit tests normal, replace the BCM.
4. Install a 3A fused jumper wire between the signal circuit terminal 1 and the ground circuit terminal 3. Verify the scan tool Traction Control Switch parameter is Active.
• If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
5. If all circuits test normal, test or replace the traction control switch.
Component Testing
1. Ignition OFF, disconnect the harness connector at the traction control switch.
2. Test for infinite resistance between the signal terminal 1 and the ground terminal 3 with the switch in the open position.
• If not the specified value, replace the traction control switch.
3. Test for less than 2 ohms between the signal terminal 1 and the ground terminal 3 with the switch in the closed position.
• If greater than the specified range, replace the traction control switch.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Accessory Switch Replacement (without RPO SLT) Accessory Switch Replacement (without RPO SLT)Accessory Switch Replacement (with RPO SLT) Accessory Switch Replacement (with RPO SLT)
* Control Module References Control Module References for BCM or IPC replacement, programming and setup