RL V6-3474cc 3.5L (1998)
Engine Control Module: Service and Repair
ECM Substitution and Reset Procedure
Known-Good PCM Substitution
Use the following procedure if you need a known-good PCM to test a vehicle. It allows you to swap an PCM from a "donor" vehicle without having to
program it to the test vehicle's ignition key.
1. Cut a temporary ignition key for the test vehicle with a non-immobilizer key blank.
2. Remove the PCM from the test vehicle.
3. Write the test vehicle's VIN on the PCM you just removed to avoid confusing it with the donor vehicle's PCM.
4. Remove the known-good PCM from the donor vehicle, and install it in the test vehicle.
5. Tape the donor vehicle's ignition key head-to-head to the test vehicle's temporary key. The PCM will recognize the code from the donor vehicle's
key and allow you to start the engine with the temporary key.
6. After completing your tests, reinstall both PCM's, and destroy the temporary key.
If the inspection for a particular code requires voltage or resistance checks at the PCM connectors, remove the right door sill molding. Pull the carpet
back to expose the PCM. Unbolt the PCM cover, and connect the backprobe sets and a digital multimeter as described below. Check the system
according to the procedure described for the appropriate code(s) listed.
