Trouble Codes

During the process of controlling various subsystems, the ECM and BCM continually monitor operating conditions for possible system malfunction(s). By comparing system conditions against standard operating limits, certain circuit and component malfunctions can be detected.

An alpha-numeric trouble code is stored in computer memory when a problem is detected. These trouble codes can later be displayed to aid technician in diagnosing the system.

Certain system malfunctions cause computer-controlled diagnostic messages and/or telltales to appear, indicating that service is required. When a subsystem circuit exceeds preprogrammed limits, a system malfunction is indicated and the BCM provides certain back-up functions known as "FAILSOFT". A typical, "FAILSOFT" action would be the substitution of a fixed input value when a sensor is detected to be open or shorted.