Charging System - Generators & Regulators: Operation

The amount of amperage produced by the generator is controlled by Electronic Voltage Regulator (EVR) circuitry within the PCM. EVR circuity is connected in series with the generator field driver terminal and ground. A Battery Temperature Sensor (BTS) is located on rear of front bumper beam on all models except Avenger, Neon and Sebring Coupe, and is used to sense battery temperature. On Avenger and Sebring Coupe, BTS is located within PCM. On Neon, BTS is located on bottom of battery tray. Sensed battery temperature and data from monitored line voltage is used by PCM to adjust battery charging rate. This is accomplished by cycling the ground path to control the strength of generator rotor magnetic field. PCM then compensates and regulates generator amperage output accordingly. The PCM monitors critical input to control fuel injection, ignition, emission and other engine management functions. The PCM is also programmed to monitor charging system related circuits.

Battery feed to PCM.
Generator field control.
Battery charging voltage (high & low).

If a problem is sensed in a monitored circuit, a Diagnostic Trouble Code (DTC) will be stored in PCM memory and Malfunction Indicator Light (MIL) will illuminate, provided specific criteria have been met. DTCs can be read using MIL or Chrysler's Diagnostic Readout Box (DRB-III).

NOTE: DTC is erased from memory if failure does not reoccur after 50 engine starts.

Certain DTCs cause MIL to illuminate and engine controller to enter limp-in mode. In limp-in mode, engine controller attempts to compensate for particular component failure by substituting information from other sources. This allows vehicle operation until proper repairs are made.