Self-Diagnostic System
WARNING: This page is about a different car, the 1995 Plymouth Voyager, 1995 Plymouth Grand Voyager, 1995 Dodge Grand Caravan, and 1995 Dodge Caravan. However, it is still accessible from the selected car via links, so may be relevant.
The PCM monitors several different circuits of engine control system. If a problem is sensed with a monitored circuit, PCM will store a trouble code to aid technician in diagnosis of system. The CHECK ENGINE light or DRB can be used to read trouble codes.