Diagnostic Trouble Code (DTC) Information ECM-A12B

Condition 

A fault message is transmitted to the engine control module (ECM) and the diagnostic trouble code (DTC) is stored if a fault is detected in the brake control module (BCM). Diagnostic trouble codes (DTCs) for the vehicle speed sensor (VSS) signal are also stored in the brake control module (BCM).

Substitute Value 

• The speed signal from the brake control module (BCM) is set at 0 km/h.

Possible Source 

• Contact resistance in the control area network (CAN) terminals
• Open-circuit in one or both CAN cables
• Short-circuit to ground, voltage or each other in one or both signal cables
• Damaged brake control module (BCM)
• Damaged engine control module (ECM).

Fault symptom[s] 

• Malfunction indicator lamp (MIL) lit.