1998 Subaru Forester BaseFACTORY OEM SERVICE PROCEDURE

Test 10: Motor &/Or Relay Circuit Problem

  1. Turn ignition off. Disconnect ABSCM/HU connector. Turn ignition on. Measure voltage between ground and ABSCM/HU connector terminal No. 25. See Figure . If voltage is 10-15 volts, go to next step. If voltage is not 10-15 volts, repair wiring harness between battery and ABSCM/HU. Check SBF-holder fuse.
  2. Turn ignition off. Measure resistance between ground and ABSCM/HU control terminal No. 26. If resistance is less than .5 ohm, go to next step. If resistance is more than .5 ohm, repair wiring harness between ground and ABSCM/HU.
  3. Start engine and run at idle. Measure voltage between ground and ABSCM/HU connector terminal No. 1. See Figure . If voltage is 10-15 volts, go to next step. If voltage is not 10-15 volts, repair wiring harness between battery, ignition switch and ABSCM/HU connectors.
  4. Turn ignition off. Measure resistance between ground and ABSCM/HU connector terminal No. 23. If resistance is less than .5 ohm, go to next step. If resistance is more than .5 ohm, repair wiring harness between ground and ABSCM/HU.
  5. Perform sequence control using diagnostic connector. See SELF-DIAGNOSTIC SYSTEM  . If motor revolution noise (buzz) is heard when performing sequence control, go to next step. If motor revolution noise (buzz) is not heard when performing sequence control, replace ABSCM/HU.
  6. Check contacts at battery, generator and ABSCM/HU connectors. Clean contacts as needed. Go to next step.
  7. Reconnect all connectors. Erase memory. Recheck for trouble codes. If same trouble code returns, replace ABSCM/HU. If other trouble codes exist, go to proper test procedure. If no trouble codes exist, problem was a temporary poor contact. Check harness and connectors.
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When to See a Mechanic

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

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

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