1986 Cadillac SevilleFACTORY OEM SERVICE PROCEDURE

Electronic Control Module

The ECM is mounted under the right end of instrument panel and consists of various printed circuit boards mounted in a metal box. All sensor inputs are fed into ECM and are processed to produce proper pulse duration for injectors, correct idle speed, and proper spark advance. All sensors send analog inputs, which are converted to digital inputs before processing.

Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

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When to See a Mechanic

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

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