Dodge Durango

 Service Manual

Charging System » Description and operation
Charging system

DESCRIPTION

The charging system consists of:

• Generator
• Electronic Voltage Regulator (EVR) circuitry within the Powertrain Control Module (PCM)
• Ignition switch (refer to Ignition System for information)
• Battery (refer to Battery for information)
• Battery temperature sensor
• Check Gauges Lamp (if equipped)
• Voltmeter (refer to Instrument Panel and Gauges for information)
• Wiring harness and connections (refer to Wiring for information)

OPERATION

The charging system is turned on and off with the ignition switch. The system is on when the engine is running and the ASD relay is energized. When the ASD relay is on, voltage is supplied to the ASD relay sense circuit at the PCM. This voltage is connected through the PCM and supplied to one of the generator field terminals (Gen. Source +) at the back of the generator.

The amount of direct current produced by the generator is controlled by the EVR (field control) circuitry contained within the PCM. This circuitry is connected in series with the second rotor field terminal and ground.

A battery temperature sensor, located in the battery tray housing, is used to sense battery temperature.

This temperature data, along with data from monitored line voltage, is used by the PCM to vary the battery charging rate. This is done by cycling the ground path to control the strength of the rotor magnetic field. The PCM then compensates and regulates generator current output accordingly.

All vehicles are equipped with On-Board Diagnostics (OBD). All OBD-sensed systems, including EVR (field control) circuitry, are monitored by the PCM.

Each monitored circuit is assigned a Diagnostic Trouble Code (DTC). The PCM will store a DTC in electronic memory for certain failures it detects. Refer to On-Board Diagnostics in Emission Control System for more DTC information.

The Check Gauges Lamp (if equipped) monitors: charging system voltage, engine coolant temperature and engine oil pressure. If an extreme condition is indicated, the lamp will be illuminated. This is done as a reminder to check the three gauges. The signal to activate the lamp is sent via the multiplexed bus circuits. The lamp is located on the instrument panel. Refer to Instrument Panel and Gauges for additional information.

Charging system

Generator

Battery temperature sensor

Electronic voltage regulator