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Rear Light Failure Sensor

  1. If rear light failure warning light is not operating correctly, disconnect harness connector from rear light failure sensor located in trunk, and ground terminal No. 4. Turn ignition on and ensure warning light glows. Start engine and ensure warning light goes out. If operation is not as specified, check bulb. If bulb is okay, go to next step.
  2. Using a DVOM, check for continuity between ground and wire harness side terminals No. 1, 2, 3, 9 and 11. See Figure. Continuity should exist on all terminals. Terminals No. 1, 2, 3 and 9 will read slight resistance, as they are grounded through bulbs. If continuity is as specified, go to next step. If continuity is not as specified, repair wiring.
  3. Check for voltage between terminal No. 3 and ground. With headlights off, no voltage should be present. Turn headlights on. If battery voltage is present, go to next step. If battery voltage is not present, check headlight switch and wiring.
  4. Check for voltage between terminal No. 4 and ground. With ignition switch in LOCK or ACC position, no voltage should be present. Turn ignition on. If battery voltage is present, go to next step. If battery voltage is not present, check ignition switch and wiring.
  5. Check for voltage between ground and terminal No. 7. With brake pedal released, no voltage should be present. Depress brake pedal. If battery voltage is present, go to next step. If battery voltage is not present, check brake switch and wiring.
  6. Check for voltage between terminal No. 8 and ground. With ignition switch in LOCK or ACC position, no voltage should be present. Turn ignition on. If battery voltage is not present, check ignition switch and wiring. If battery voltage is present, test is complete. Substitute known good rear light failure sensor and recheck warning light operation.
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