DTC code C0561-77

[desert sonic]

Hello,

Interested in getting some guidance on DTC code C0561-77, for a 2015 sonic LTZ 1.4L turbo. This code is the latest issue with this car. Some background leading up to this issue:

1.Car problems started as high temp warning light; flushed coolant system using flush machine.
2. Noticed crack in overflow reservoir during inspection after flush; replaced reservoir.
3. Continued getting high temp warning; had dealership assist with diagnosis, conclusion: tstat.
4. Replaced tstat, housing, gasket.
5. Started getting CEL light randomly (sometimes would show, sometimes wouldn't; CEL would be on while running, but after engine stopped running, CEL wouldn't show on restart; sometimes wouldn't show at all during run, stop, or restart).
6. Used scanner to pull code C0156-77, checked code list for explanation:
- System Disabled Information Stored Engine Speed Out of Range
7. Began researching DTC code, getting various results from: replacing ECM, BCM, EBCM, grounding issue, glue on electrical connectors confused, etc. which translated to me as "electrical issue with no clear cut answer"

So, now I'm hoping I can get some info from this forum. Not really interested in throwing money/parts at the car until this issue magically goes away.

 

[wasteoffilm]

That's an ABS brake system code, saying there is a communication issue with the engine computer.

Check again for any other codes, otherwise, it seems like you might be replacing computer(s).

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DTC C0561 (ANTILOCK BRAKE SYSTEM)
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 77 : System Disabled Information Stored Engine Speed Out of Range

DTC C0561 78 : System Disabled Information Stored Acceleration Pedal Position Out of Range

DTC C0561 79 : System Disabled Information Stored Transmission Gear Invalid Data

Circuit/System Description
The electronic brake control module disables the traction and the stability control when other electronic control modules set DTCs for components that effect the operation of the brake system.

Conditions for Running the DTC
Engine Running.
Ignition voltage is greater than 8 V.
Conditions for Setting the DTC
The electronic brake control module receives an invalid serial data message from another module more than ten times.

Action Taken When the DTC Sets
The ABS system remains functional.
The electronic brake control module disables the stability control for the entire 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 drive cycles have occurred.
Diagnostic Aids
This DTC indicates there are no problems in the brake system. The body control module, engine control module, and transmission control module should be checked for a possible fault first.
Inspect the serial data circuits and connections at the engine control module and the electronic brake control module. They should be free from sources of electromagnetic interference and the connections should be clean and tight.
Reference Information
Schematic Reference
Antilock Brake System Schematics

Connector End View Reference
Component Connector End Views

Description and Operation
ABS Description and Operation

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
C0561 77 or C0561 78
Ignition ON.
Verify there are no other DTCs set.
If any other DTCs are set
Refer to the Diagnostic Trouble Code (DTC) List - Vehicle .

If no other DTCs are set
Replace the K20 Engine Control Module.
Verify the DTC does not set while operating the vehicle within the conditions for Running the DTC.
If the DTC sets
Replace the K17 Electronic Brake Control Module.

If the DTC does not set
All OK.
C0561 79
Ignition ON.
Verify there are no other DTCs set.
If any other DTCs are set
Refer to the Diagnostic Trouble Code (DTC) List - Vehicle .

If no other DTCs are set
Replace the K71 Transmission Control Module.
Verify the DTC does not set while operating the vehicle within the conditions for Running the DTC.
If the DTC sets
Replace the K17 Electronic Brake Control Module.

If the DTC does not set
All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Electronic Brake Control Module, Engine Control Module, or Transmission Control Module replacement, programming and setup