CHARGING SYSTEM
TABLE OF CONTENTS
page page
DESCRIPTION AND OPERATION
CHARGING SYSTEM OPERATION ............1
GENERATOR .............................1
BATTERY TEMPERATURE SENSOR—PCM
INPUT ................................2
REMOVAL AND INSTALLATION
GENERATOR—2.7L .......................2
GENERATOR—3.2/3.5L ....................2
SPECIFICATIONS
TORQUE ................................3
GENERATOR .............................3
DESCRIPTION AND OPERATION
CHARGING SYSTEM OPERATION
DESCRIPTION
The charging system consists of:
• Generator
• Electronic Voltage Regulator (EVR) circuitry
within the Powertrain Control Module (PCM)
• Ignition switch (refer to the Ignition System sec-
tion for information)
• Battery (refer to the Battery section for informa-
tion)
• Battery temperature sensor
• Voltmeter (refer to the Instrument Panel and
Gauges section for information)
• Wiring harness and connections (refer to the
Wiring section 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 genera-
tor field terminals (Gen. Source +) at the back of the
generator.
The amount of DC current produced by the gener-
ator is controlled by the EVR (field control) circuitry
contained within the PCM. This circuitry is con-
nected in series with the second rotor field terminal
and ground.
A battery temperature sensor is used to sense bat-
tery 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 Diagnos-
tics (OBD). All OBD-sensed systems, including EVR
(field control) circuitry, are monitored by the PCM.
Each monitored circuit is assigned a Diagnostic Trou-
ble Code (DTC). The PCM will store a DTC in elec-
tronic memory for certain failures it detects. Refer to
On-Board Diagnostics in the Emission Control Sys-
tem section for more DTC information.
The Check Gauges Lamp (if equipped) monitors:
charging system voltage, engine coolant tempera-
ture and engine oil pressure. If an extreme condition
is indicated, the lamp will be illuminated. This is
done as reminder to check the three gauges. The sig-
nal to activate the lamp is sent via the PCI bus cir-
cuits. The lamp is located on the instrument panel.
Refer to the Instrument Panel and Gauges section for
additional information.
GENERATOR
DESCRIPTION
The generator is belt-driven by the engine. It is
serviced only as a complete assembly. If the genera-
tor fails for any reason, the entire assembly must be
replaced. The generator produces DC voltage.
OPERATION
As the energized rotor begins to rotate within the
generator, the spinning magnetic field induces a cur-
rent into the windings of the stator coil. Once the
generator begins producing sufficient current, it also
provides the current needed to energize the rotor.
The Y type stator winding connections deliver the
induced AC current to 3 positive and 3 negative
diodes for rectification. From the diodes, rectified DC
current is delivered to the vehicles electrical system
through the generator, battery, and ground terminals.
LH CHARGING SYSTEM 8C - 1
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