Dodge Dakota (ND). Manual - part 226
MODULE-FRONT CONTROL
DESCRIPTION
The Front Control Module (FCM) (2) is a micro con-
troller based module located in the left front corner of
the engine compartment. The FCM mates to the
Power Distribution Center (PDC) (1) to form the Inte-
grated Power Module (IPM). The IPM connects
directly to the battery and provides the primary means
of circuit protection and power distribution for all vehi-
cle electrical systems. The front control module con-
trols power to some of these vehicle systems electrical
and electromechanical loads based on inputs received
from hard wired switch inputs and data received on
the Controller Area Network (CAN) bus circuit.
OPERATION
As messages are sent over the Controller Area Network (CAN) bus circuit, the Front Control Module (FCM) reads
these messages and controls power to some of the vehicles electrical systems by completing the circuit to ground
(low side driver) or completing the circuit to 12 volt power (high side driver). The following functions are controlled
by the FCM:
•
Front turn signals
•
Stop, turn signal and tail lamps
•
Front and rear hazard warning lamps
•
Headlamps
•
Fog Lamps
•
Daytime running lamps - if equipped
•
Horn
•
Windshield and liftgate wiper and washer systems
•
Transfer case shifting
•
Trailer tow wiring output
•
Rear window defroster power and timing
The FCM provides the following features for the above function:
•
It operates the electric transfer case mechanism, replacing a stand-alone module.
•
It flashes lamps in response to turn signal, Remote Keyless Entry and Vehicle Theft Security Alarm inputs.
•
It sounds the horn in response to Remote Keyless Entry and Vehicle Theft Security Alarm inputs.
•
It turns off the horn in the event of excessively long operation that could otherwise damage the horn.
•
It minimized voltage variations to the headlamps to extend bulb life and to equalize the light output from the
lamps, which might otherwise differ due to variations in wiring resistance.
•
If the headlamps are left on, it automatically turns them off after eight minutes to protect the battery from dis-
charge.
•
It monitors battery voltage and turns off non-essential functions such as the fog lamps, rear window defogger
and heated seats if necessary to conserve battery power.
•
It operates the high-beam headlamps at reduced intensity by pulse-width modulation of the power supply to
provide the daytime running lamps.
8E - 160
ELECTRONIC CONTROL MODULES - SERVICE INFORMATION
ND