LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2000 >> SC 400 >> Repair and Diagnosis >> Body & Frame >> Door Locks >> Anti-Theft Systems >> Circuit Tests >> Door Key Lock & Unlock Switch Circuit
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Door Key Lock & Unlock Switch Circuit

  1. Remove door trim panel and service hole cover to access door key lock cylinder (door key lock and unlock switch is built into door key lock). Disconnect 3-pin door key lock and unlock switch connector. Using an ohmmeter, check continuity between switch connector terminals No. 1 (Green wire on left door; Green/White wire on right door), No. 2 (White/Black wire) and No. 3 (Green/Yellow wire) with switch in specified position. See DOOR KEY LOCK & UNLOCK SWITCH CONTINUITY  table. If continuity is as specified, go to next step. If continuity is not as specified, replace door key lock and unlock switch.
    DOOR KEY LOCK & UNLOCK SWITCH CONTINUITY

    Switch Position Terminals No. Continuity
    Lock 2 & 3 Yes
    Unlock 1 & 2 Yes
    Neutral 2 & 3; 1 & 2 No
  2. Check circuits for faults between door key lock and unlock switch, anti-theft/door lock control ECU and body ground. See WIRING DIAGRAMS . Repair or replace as necessary. If circuits are okay, check anti-theft/door lock control ECU pin voltages. See ANTI-THEFT/DOOR LOCK CONTROL ECU PIN VOLTAGE TESTS  under COMPONENT TESTS. Replace as necessary and retest system operation. Proceed to next test listed in appropriate SYMPTOM DIAGNOSIS table under TROUBLE SHOOTING .