Trooper LS V6-3.5L (1998)
Engine Control Module: Description and Operation
Wiring and Connectors
Wiring Harness Service
The control module harness electrically connects the control module to the various solenoids, switches and sensors in the vehicle engine compartment
and passenger compartment.
Replace wire harnesses with the proper part number replacement.
Because of the low amperage and voltage levels utilized in powertrain control systems, it is essential that all wiring in environmentally exposed areas
be repaired with crimp and seal splice sleeves.
The following wire harness repair information is intended as a general guideline only. Refer to Chassis Electrical for all wire harness repair
procedures.
Connectors and Terminals
Use care when probing a connector and when replacing terminals. It is possible to short between opposite terminals. Damage to components could
result. Always use jumper wires between connectors for circuit checking. NEVER probe through Weather-Pack seals. Use an appropriate connector
test adapter kit which contains an assortment of flexible connectors used to probe terminals during diagnosis. Use an appropriate fuse remover and test
tool for removing a fuse and to adapt the fuse holder to a meter for diagnosis.
Open circuits are often difficult to locate by sight because oxidation or terminal misalignment are hidden by the connectors. Merely wiggling a
connector on a sensor, or in the wiring harness, may temporarily correct the open circuit. Intermittent problems may also be caused by oxidized or
loose connections.
Be certain of the type of connector/terminal before making any connector or terminal repair. Weather-Pack and Com-Pack III terminals look similar,
but are serviced differently.
General Description
The Powertrain Control Module (PCM) is located in the passenger compartment.
The PCM constantly monitors the information from various sensors, and controls the systems that affect vehicle performance. The PCM performs the
diagnostic function of the system. It can recognize operational problems, alert the driver through the Malfunction Indicator Light (MIL) and store a
Diagnostic Trouble Code (DTC) or DTC(s) which identify the problem areas to aid the technician in making repairs. The PCM is designed to process
the various input informations and then sends the necessary electrical responses to control fuel delivery, spark timing and other emission control
systems. The input information has an interrelation to more than one output, therefore, if the one input failed, it could affect more than one system
operation. Refer to Driveability and Emission in Engine section and Automatic Transmission in Transmission section.
