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Home >> Lexus >> 1999 >> GS 400 >> Repair and Diagnosis >> Body & Frame >> Body, Cab Control Systems >> Body Control Systems >> Circuit Tests >> Taillight Relay Circuit
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Taillight Relay Circuit

NOTE: If LEXUS scan tool is available, start test from step  1. If this scan tool is not available, start test from step  2.
  1. Using scan tool, operate taillight relay in ACTIVE TEST. If taillight relay does not operate (taillights do not operate), go to next step. If taillight relay operates (taillights operate), go to next test listed in appropriate SYMPTOM DIAGNOSIS table under TROUBLE SHOOTING .
  2. Check taillight relay. See TAILLIGHT RELAY  under COMPONENT TESTS. Replace taillight relay as necessary. Retest system operation. If taillight relay is okay, go to next step.
  3. Check circuits for faults between taillight relay, body control ECU No. 2 and battery. See WIRING DIAGRAMS . Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate SYMPTOM DIAGNOSIS table under TROUBLE SHOOTING .
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