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Home >> Lexus >> 2000 >> SC 400 >> Repair and Diagnosis >> Steering >> Steering Column >> Power Tilt Steering Column Systems >> Circuit Tests >> Door Courtesy Switch Circuit
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Door Courtesy Switch Circuit

  1. Open driver's door and ensure door courtesy light illuminates. If door courtesy light illuminates, go to next step. If door courtesy light does not illuminate, check and repair door courtesy light circuit. See appropriate wiring diagram in ILLUMINATION/INTERIOR LIGHTS article.
  2. Turn ignition off. Remove tilt and power telescopic ECU from its mounting, leaving wiring harness connector attached. Measure voltage between ground and by backprobing rear of terminal No. 2 (Red/Black wire) with voltmeter positive lead at 18-pin ECU harness connector T10. See Figure. If battery voltage exists with driver's door closed and battery voltage is less than one volt with driver's door open, go to next test listed in SYMPTOM DIAGNOSIS  table under TROUBLE SHOOTING. If voltage is not as specified, go to next step.
  3. Check and repair open wiring harness between tilt and power telescopic ECU and driver's door courtesy switch. See WIRING DIAGRAMS .
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