Antilock Brake System (North America)

DTC C0550 (North America)

Circuit Description

The antilock brake system (ABS) control module performs various diagnostic checks on itself. If it finds a problem, it sets DTC C0550.

This procedure checks whether there is a poor ground connection for the electronic brake control module (EBCM).

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C0550 Electronic Control Unit (ECU) Performance

Conditions for Running the DTC

* Vehicle speed is greater than 6 km/h (4 mph) with the brake pedal not applied
or
* Vehicle speed is greater than 15 km/h (9 mph) and the brake pedal is actuated.

Conditions for Setting the DTC

* A connector terminal is corroded.
* The EBCM is malfunctioning.

Action Taken When the DTC Sets

The ABS is disabled, and the ABS warning lamp is turned ON. The electronic brake force distribution (EBD) is disabled. If the failure is intermittent, the control module will enable the system at the next ignition cycle and will store a history DTC C0550.

Conditions for Clearing the DTC

The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.

Diagnostic Aids

It is very important to perform a thorough inspection of the wiring and the connectors. Failure to inspect the wiring and the connectors carefully and completely may result in misdiagnosis, causing part replacement with the reappearance of the malfunction.

Test Description

The numbers below refer to the step numbers on the diagnostic table.
4. This step begins the testing for a poor voltage or ground connection.