GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The body control module (BCM) sends a state of health serial data message to the electronic brake control module (EBCM) within 5.5 seconds after the ignition is turned ON.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C0291 Lost Communication with BCM

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

The EBCM fails to receive serial data from the BCM.

Action Taken When the DTC Sets

The EBCM sets this information-only DTC as a current DTC for as long as the conditions for setting the DTC are present.

Conditions for Clearing the DTC

The conditions for setting the DTC are no longer present and you use the scan tool Clear DTCs function.

Step

Action

Yes

No

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Scan Tool Does Not Communicate with Class 2 Device in Computer/Integrating Systems

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information