PROM Replacement

1. Remove the ECM from the passenger compartment as described in the appropriate workshop manual.

2. Follow the instructions packed with the new PROM to remove the old PROM from the ECM and install the new PROM in its place. A copy of the instruction sheet is attached to this Service Bulletin for your reference.

NOTE: On Sheet 1 of the instructions, you are told to make sure that the new PROM bears the same part number as the one being removed. This Service Bulletin requires that you use a different part number, as listed above.

3. Install and connect the ECM as described in the appropriate workshop manual.

4. Connect a jumper lead between the A and C terminals of the ECM diagnosis connector. Turn the ignition on:
A. If Code 12 flashes four times, with no other codes present, the PROM is installed correctly. Go on with this procedure.

B. If Code 51 flashes or the "Check Engine" light remains on constantly, see Sheet 2 of the PROM installation instructions. Do not go on with this procedure until the problem is corrected and Code 12 appears.

5. Remove the jumper lead from the ECM dignostic connector and complete the ECM installation.