Engine Control Module: Service and Repair

When replacing production ECM, transfer Production Broadcast Code and Production ECM labels to the service controller label.
1. Disconnect battery ground cable.
2. Remove ECM mounting hardware and disconnect electrical connectors.
3. Remove ECM from under instrument panel on all 1988 models and 1984-85 C and K Series. On 1984-85 G and P Series, remove ECM from under driver's seat.
4. Reverse procedure to install. Replacement ECMs are not supplied with a PROM. If PROM is to be reused, care must be taken when removing from damaged ECM, refer to PROM, Replace procedure.