Circuit Test B - EEC-V Power Relay

1991 Mercury Tracer Base, 4D Sedan, AutomaticSECTION Circuit Test B - EEC-V Power Relay
WARNING: This page is about a different car, the 1995 Lincoln Continental. However, it is still accessible from the selected car via links, so may be relevant.

This circuit test is only intended to diagnose the following components and circuits:

  • Vehicle wiring harness circuits (VPWR, IGNITION START/RUN, B+ and Ground).
  • EEC-V power relay.
  • Constant Control Relay Module (CCRM).
  • Powertrain Control Module (PCM).
    Fig 1: EEC-V Power Relay Test Circuits
    G95B12584

  1. 1) Check VPWR Circuit Continuity

    Turn ignition off. Disconnect Idle Air Control (IAC) solenoid and EEC-V power relay wiring harness connectors. Disconnect scan tool (if applicable). Measure resistance between VPWR terminal of IAC solenoid connector and VPWR terminal of EEC-V power relay. If resistance is less than 5 ohms, reconnect IAC solenoid and go to next step. If resistance is 5 ohms more, repair open in VPWR circuit between EEC-V power relay and IAC solenoid.
  2. 2) Check Ground Circuit To EEC-V Power Relay

    Leave ignition off and EEC-V power relay disconnected. Measure resistance between Ground terminal of EEC-V power relay and negative battery terminal. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, go to step 5).
  3. 3) Check Voltage To EEC-V Power Relay

    Leave ignition off and EEC-V power relay disconnected. Connect DVOM negative lead to negative battery terminal. Measure voltage at B+ terminal of EEC-V power relay connector. Turn ignition on. Measure voltage at IGN START/RUN. If voltage is less than 10.5 volts, repair open circuit and repeat QUICK TESTΒ  . If voltage is more than 10.5 volts, replace EEC-V power relay and repeat QUICK TESTΒ  .
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 3) to step 5). No test procedures have been omitted.
  4. 5) Check Ground Circuit From CCRM

    Leave ignition off and EEC-V power relay disconnected. Disconnect CCRM. Measure resistance between pin No. 15 (Black wire) of CCRM wiring harness connector and negative terminal of battery. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in circuit and repeat QUICK TESTΒ  .
  5. 6) Check Ground Circuit Between EEC-V Power Relay & CCRM

    Leave ignition off. Measure resistance between pin No. 9 (Yellow wire) of CCRM wiring harness connector and ground circuit of EEC-V power relay connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in circuit and repeat QUICK TESTΒ  .
  6. 7) Check Ground Circuit In CCRM

    Leave ignition off. Connect ohmmeter negative lead to pin No. 15 of CCRM. Connect positive lead to terminal No. 9 of CCRM. Measure resistance. If resistance is less than 5 ohms, ground circuit is okay and testing is complete. If resistance is 5 ohms or more, verify that circuit is not shorted to power. If circuit is okay, replace CCRM and repeat QUICK TESTΒ  .
RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

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

Affiliate disclosure: We may earn a commission at no extra cost to you.

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.