Alternator & Regulator: Operation

The PCM monitors critical inputs to control fuel injection, ignition, emission and other engine management functions. The PCM has also been programmed to monitor several 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 fault code is stored in the PCM's memory and the CHECK ENGINE light will be turned on (with a few exceptions). Fault codes can be read using the CHECK ENGINE light or with the Chrysler Diagnostic Readout Box-II (DRB-II).

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

For certain fault codes, CHECK ENGINE light 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.