1987 Cadillac SevilleFACTORY OEM SERVICE PROCEDURE

Multiple Intermittent Codes: Notes

Locate combination of codes displayed. All must be "History" ("Hard") trouble codes. Follow charts indicated in previous test. The following will account for combinations of "History" ("Hard") trouble codes concerning serial data line circuit codes and/or computer memory reset codes.

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.