Engine Control Module: Service and Repair

PCM Installation:

When replacing a production Computer with a service Computer, transfer the broadcast code and production number from the production unit to the service unit. Also during replacement, the EPROM must be removed from the Computer being replaced and transferred to the new unit. Refer to MEM-CAL for replacement procedures.

REMOVAL:

1. Disconnect battery ground cable.
2. Remove coolant tank reservoir.
3. Remove PCM mounting hardware.
4. Disconnect connectors from the PCM.
5. Remove PCM from the engine compartment.
6. Transfer EPROM unit.

INSTALLATION:

1. Re-connect connectors to the PCM.
2. Install PCM mounting hardware.
3. Install coolant tank reservoir.
4. Re-connect battery ground cable.

FUNCTIONAL CHECK:

1. Turn the ignition "ON."
2. Enter diagnostics.
a. Allow Code 12 to flash four times to verify no other codes are present. This indicates the EPROM is installed properly and the PCM is functioning.
b. If trouble Codes 42, 43, or 51 occur, or if the "SERVICE ENGINE SOON" light is "ON" constantly with no codes, the EPROM is not fully seated or is defective. If not fully seated, press firmly on the ends of the EPROM.