Charging System - Generators & Regulators: Operation
Amperage produced by generator is controlled by Electronic Voltage Regulator (EVR) circuitry within Powertrain Control Module (PCM). EVR circuity is connected in series with generator field driver terminal and ground. Battery temperature sensor is located within PCM. On Neon and PT Cruiser, an inlet air temperature sensor is used instead of a battery temperature sensor. See Fig 1 and Fig 2 . PCM uses information from inlet air temperature sensor along with other stored parameters to determine values of intake air and battery temperatures. Inlet air temperature sensor value is used by PCM to determine air density. On all models, sensed battery temperature and data from monitored line voltage is used by PCM to adjust battery charging rate. This is accomplished by cycling ground path to control strength of generator rotor magnetic field. PCM then compensates and regulates generator amperage output accordingly. PCM monitors critical input to control fuel injection, ignition, emission and other engine management functions. PCM is also programmed to monitor charging system related circuits.
- Battery feed to PCM.
- Generator field control.
- Battery charging voltage (High And Low).
If a problem is sensed in a monitored circuit, a DTC will be stored in PCM memory. Voltage indicator light and Malfunction Indicator Light (MIL) will illuminate, provided specific criteria have been met. DTCs can be read using Chrysler's Diagnostic Readout Box (DRB-III). A generic scan tool may also be used for system diagnostics, but may have limited diagnostic capability.