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+B Power Source Circuit Test

NOTE: Use this procedure to check for problems in circuit between driver's power seat ECU and DOOR circuit breaker.
  1. Turn ignition off. At driver's seat, remove bolts for front vertical adjuster. Lift front end of seat cushion slightly for access to power seat ECU (do not lift too far; harness clamp may come loose). Remove power seat ECU, but leave electrical connectors attached.
  2. At connector "B" of power seat ECU, connect voltmeter negative lead to terminal No. 1, and connect positive lead to terminals No. 6 and 14. See Fig 1. If battery voltage is present, check next item listed under TROUBLE SHOOTING. If battery voltage is not present, disconnect connector "B".
  3. Measure resistance between terminal No. 1 and ground. If resistance is one ohm or more, repair open circuit. If resistance is less than one ohm, check DOOR circuit breaker.
  4. If circuit breaker is open, repair short to ground in circuit between DOOR circuit breaker and power seat ECU, or between power seat ECU and seat motors. If circuit breaker is okay, repair circuit between battery and power seat ECU.
Fig 1: Identifying Power Seat ECU Connector Terminals (LS400)
G94E47567Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002