Vue 2002-2005

Powertrain Control Module



The powertrain has electronic controls to reduce exhaust emissions while maintaining excellent drivability and fuel economy. The Powertrain Control Module (PCM) is the control center of this system. The PCM monitors numerous engine and vehicle functions. The PCM constantly looks at the information from various sensors and other inputs, and controls the systems that affect vehicle performance and emissions. The PCM also performs the diagnostic tests on various parts of the system. The PCM can recognize operational problems and alert the driver via the Malfunction Indicator Lamp (MIL). When the PCM detects a malfunction, the PCM stores a Diagnostic Trouble Code (DTC). The problem area is identified by the particular DTC that is set. The control module supplies a buffered voltage to various sensors and switches. Review the components and wiring diagrams in order to determine which systems are controlled by the PCM. The following are some of the functions that the PCM controls:

The engine fueling
The Ignition Control (IC)
The Knock Sensor (KS) system
The Evaporative Emissions (EVAP) system
The Secondary Air Injection (AIR) system (if equipped)
The Exhaust Gas Recirculation (EGR) system
The automatic transmission functions
The alternator
The A/C clutch control
The cooling fan control

Removal & Installation

2.2L & 2.4L Engines

For the 2.2L & 2.4L engines, refer to Electronic Control Module (ECM) for the removal & installation.

3.5L Engine
  1. Before servicing the vehicle, refer to the Precautions Section.
    Turn the ignition OFF when installing or removing the control module connectors and disconnecting or reconnecting the power to the control module (battery cable, Powertrain Control Module (PCM)/Engine Control Module (ECM)/Transaxle Control Module (TCM) pigtail, control module fuse, jumper cables, etc.) in order to prevent internal control module damage.

    Control module damage may result when the metal case contacts battery voltage. DO NOT contact the control module metal case with battery voltage when servicing a control module, using battery booster cables, or when charging the vehicle battery.

    In order to prevent any possible electrostatic discharge damage to the control module, do no touch the connector pins or the soldered components on the circuit board.

    Remove any debris from around the control module connector surfaces before servicing the control module. Inspect the control module connector gaskets when diagnosing or replacing the control module. Ensure that the gaskets are installed correctly. The gaskets prevent contaminant intrusion into the control module.

    The replacement control module must be programmed.

    It is necessary to record the remaining engine oil life. If the replacement module is not programmed with the remaining engine oil life, the engine oil life will default to 100 percent. If the replacement module is not programmed with the remaining engine oil life, the engine oil will need to be changed at 3,000 miles (5,000 km) from the last engine oil change.

  3. Using a scan tool, retrieve the percentage of remaining engine oil. Record the remaining engine oil life.
  5. Disconnect the battery negative cable.
  7. Disconnect the wiring harness.
  9. Depress the retaining tab and remove the Powertrain Control Module (PCM).
  11. Remove the PCM from the housing.

To install:

  1. Install the PCM into the housing bracket.
  3. Connect the wiring harness.
  5. Connect the battery negative cable.
  7. Program the PCM.


The Powertrain Control Module (PCM) is programmed with test routines that test the operation of the various systems the PCM controls. Some tests monitor internal PCM functions. Many tests are run continuously. Other tests run only under specific conditions, referred to as conditions for running a Diagnostic Trouble Code (DTC). When the vehicle is operating within the conditions for running a particular test, the PCM monitors certain parameters and determines if the values are within an expected range. The parameters and values considered outside the range of normal operation are listed as conditions for setting the DTC. When the conditions for setting the DTC occur, the PCM executes the action taken when the DTC Sets. Some DTC-s alert the driver via the Malfunction Indicator Lamp (MIL) or a message. Other DTC-s do not trigger a driver warning, but are stored in memory. The PCM also saves data and input parameters when most DTC-s are set. This data is stored in the freeze frame and/or failure records.

The DTC-s are categorized by type. The DTC type is determined by the MIL operation and the manner in which the fault data is stored when a particular DTC fails. In some cases there may be exceptions to this structure. Therefore, when diagnosing the system it is important to read the action taken when the DTC sets and the conditions for clearing the DTC.

Many intermittent open or shorted circuits come and go with harness and connector movement caused by vibration, engine torque, bumps, and rough pavement.

  1. Test the wiring harness and connectors by performing the following:

    Move the related PCM connectors and wiring while monitoring the appropriate scan tool data
    With the engine running, move the related connectors and wiring while monitoring engine operation
    If harness or connector movement affects the data displayed, the component and system operation, or the engine operation, inspect and repair the harness or connections as necessary

  3. Test the electrical connections and/or wiring by performing the following:

    Inspect for incorrect mating of the connector halves, or terminals not fully seated in the connector body, backed-out
    Inspect for improperly formed or damaged terminals. Test for incorrect terminal tension
    Inspect for poor terminal to wire connections including terminals crimped over insulation. This requires removing the terminal from the connector body
    Inspect for corrosion or water intrusion. Pierced or damaged insulation can allow moisture to enter the wiring. The conductor can corrode inside the insulation with little visible evidence. Look for swollen and stiff sections of wire in the suspect circuits
    Inspect for wires that are broken inside the insulation