1988 Jeep WagoneerFACTORY OEM SERVICE PROCEDURE

Electronic Control Unit (Ecu)

ECU is a digital microprocessor computer. Data sensors provide the ECU with engine operating information in varying electrical signals. ECU calculates this information and corrects air/fuel ratio, ignition timing, and emission control as needed to maintain efficient engine operation. Other ECU output signals control upshift indicator light (manual transmission only), ignition module dwell and A/C clutch operation.

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.