1987 Chevrolet R 10 P/U 2WD V8-454 7.4LFACTORY OEM SERVICE PROCEDURE

Engine Control Module: Service and Repair



*** THIS PROCEDURE HAS BEEN UPDATED BY TSB # 88-42, dated 9/87

Some replacement ECM's may come with a replacement PROM already installed in them. If this situation occurs, remove prom from old ECM and install in rebuilt ECM.

When replacing a production ECM with a service ECM, transfer the broadcast code and production number from the production unit to the service unit. Also, during replacement, the PROM, and if equipped, the CALPAK must be removed from the ECM being replaced and transferred to the new unit. Refer to "PROM, REPLACE" and "CALPAK, REPLACE" for procedure.

1. Disconnect battery ground cable.
2. Remove right side kick panel, then disconnect two ECM electrical connectors.
3. Remove ECM mounting hardware.
4. Remove ECM from passenger compartment.
5. Reverse procedure to install.


Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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