The Powertrain Control Module (PCM) performs many functions on your vehicle. The module accepts information from various engine sensors and computes the required fuel flow rate necessary to maintain the correct amount of air/fuel ratio throughout the entire engine operational range.
Based on the information that is received and programmed into the PCM's memory, the PCM generates output signals to control relays, actuators and solenoids. The PCM also sends out a command to the fuel injectors that meters the appropriate quantity of fuel. The module automatically senses and compensates for any changes in altitude when driving your vehicle.
REMOVAL & INSTALLATION
See Figures 1, 2, 3, 4, 5, 6, 7 and 8
- Turn the ignition switch OFF .
- Disconnect the negative battery cable.
- Remove the right hand engine splash shield.
- Unfasten the horn attaching bolt, then detach the electrical connector and remove the horn.
- Unfasten the module-to-bracket retaining screws, then slide the PCM out of the mounting bracket.
- Detach the electrical harness connectors from the PCM.
- Remove the retainer from the PCM.
If you are replacing the PCM on a 1995-96 model:
- Remove the Electronic Programmable Read Only Memory (EPROM) module, also known as the KS module, cover.
- Remove the KS module by squeezing both retaining clips together and at the same time, grasp it at both ends and lift it up out of the socket.
Before replacement of a defective computer control module, first check the resistance of each PCM controlled solenoid.
- If the PCM is being replaced, open the package on the new PCM and verify that the PCM numbers match or an updated number is given before you attempt installation.
If you have a 1995-96 model:
- Install the EPROM into the PCM.
- Install the EPROM cover and tighten the retaining screws to 25-28 inch lbs. (3 Nm).
- Install the PCM retainer.
- Attach the module electrical harness connectors.
- Position the PCM in the vehicle, then install the module-to-bracket retaining screws.
- Install the horn, attach the electrical connector, then fasten with the horn attaching bolt. Tighten the bolt to 6-9 ft. lbs. (8-12 Nm).
- Install the right hand splash shield.
- Check that the ignition switch is OFF , then connect the negative battery cable.
- Enter the self-diagnostic system and check for trouble codes to be sure the PCM and the KS module are properly installed. For details, refer to the procedure for checking trouble codes.