Engine Control Module: Service and Repair

Description:

The ECM is programmed from the factory and has no replaceable calibration chip.


When replacing the production Engine Control Module (ECM) with a service ECM (controller), it is important to transfer the broadcast diagnostic trouble code and production ECM number to the service ECM label. Please do not record on ECM cover. This will allow positive identification of ECM parts throughout the service life of the vehicle.

Caution:
- To prevent internal ECM damage, the ignition must be "OFF" when disconnecting or reconnecting power to ECM (for example; battery cable, ECM pigtail, ECM fuse, jumper cables etc.)
- To prevent possible Electronic Discharge damage to the ECM, Do not touch the connector pins or soldered components on the circuit board.

REMOVAL
1. Negative battery cable.
2. Lower trim panel at console (4 fasteners).
3. Air Conditioning Heater transfer tube.
4. ABS controller electrical connector (1) (if equipt).
5. ABS controller (4 fasteners) (if equipt).
6. Four (4) fasteners for ECM bracket.
7. ECM electrical connectors (2).
8. ECM from under dash, bracket still attached.

INSTALLATION
1. ECM and bracket under dash.
2. Four (4) fasteners and tighten.
3. Two (2) ECM electrical connectors.
4. ABS controller and four (4) fasteners (if equipt).
5. ABS controller electrical connector (if equipt).
6. Air Conditioning Heater transfer tube.
7. Lower trim panel at console (4 fasteners).
8. Negative battery cable.

FUNCTIONAL CHECK
1. Turn ignition "ON".
2. Enter diagnostics test mode.
a. Allow Diagnostic Trouble Code (DTC) 12 to flash four times to verify no other DTC(s) are present. This indicates the reprogrammed ECM is functioning properly.
b. If DTC 51 occurs, or if the malfunction indicator lamp is "ON" constantly with no DTC(s), the ECM is defective.

^ If it is necessary to replace the ECM, follow the previous removal instructions.