Alternator & Regulator: Operation

The PCM, monitors critical input to control fuel injection, ignition, emission and other engine management functions. The PCM has also been programmed to monitor following charging system related circuits:

Battery Feed To PCM
Alternator Field Control
Battery Charging Voltage (High And Low)

If a problem is sensed in a monitored circuit, a trouble code is stored in PCM memory and the Malfunction Indicator Light (MIL) will illuminate (with a few exceptions). Trouble codes can be read using the MIL or with the Chrysler Collision Detection (CCD) Diagnostic Readout Box (DRB).

NOTE: Trouble codes remain in memory for 50 engine starts. Trouble code is erased from memory if failure does not reoccur.

For certain trouble codes, MIL will illuminate and PCM will enter limp-in mode. In limp-in mode, PCM attempts to compensate for particular component failure by substituting information from other sources. This allows vehicle operation until proper repairs are made.