1985 Jeep Pickup J20FACTORY OEM SERVICE PROCEDURE

Electronic Control Unit

The electronic control unit (ECU) has 6 wires that lead to 2-wire and 4-wire connectors.

The White and Red wires leading to the 2-wire connector are ignition feed circuits - the White wire for cranking, the Red wire for engine running.

The electronic control unit uses the Green wire to turn power to the ignition coil off and on. The Orange and Violet wires are used to transmit signals from the distributor's sensor to the control unit. The Black wire supplies the distributor ground circuit.

NOTE: The ECU is sealed to resist moisture, vibration, dirt and atmospheric conditions. It is not repairable and must be serviced as a complete unit.
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.

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