Engine Control Module: Service and Repair

Need a step-by-step guide?

Get an AI-powered repair guide with parts lists, cost estimates, and clear instructions for your 1985 Oldsmobile.

AI Repair Guides

1. Disconnect battery ground cable.
2. Disconnect numbered and lettered connectors from ECM.
3. Remove ECM mounting hardware, then the ECM from the passenger compartment.
4. Reverse procedure to install.

NOTE: Replacement ECM's are not equipped with engine calibration units (PROMs). If the PROM is to be reused, care should be taken when removing it from defective ECM. See Prom, Replace for proper removal procedure.