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+B Power Source Circuit Test

NOTE: Use this procedure to check circuit between power seat ECU and POWER (30-amp) fuse in instrument panel junction block.
  1. Ensure ignition is off. At driver's seat, remove bolts for front vertical adjuster. Lift front end of seat slightly for access to power seat ECU connectors. Backprobe for voltage between ECU harness connector "A", terminals No. 7 (White/Black wire) and No. 8 (Blue/White wire). See Fig 1. If battery voltage exists, see next test listed in SYSTEM TESTS INDEX  table. If battery voltage does not exist, go to next step.
  2. Disconnect power seat ECU harness connector "A". Measure resistance between power seat ECU harness connector "A", terminal No. 7 and ground. If resistance is one ohm or less, go to next step. If resistance is greater than one ohm, repair open or high resistance in ground circuit (White/Black wire). See WIRING DIAGRAMS .
  3. Check AM1 (40-amp) fuse and POWER (30-amp) fuse in instrument panel fuse block. If either fuse is faulty, repair short to ground in Black/Red wire or Blue/White wire between battery and power seat ECU, or between power seat ECU and seat motors. See WIRING DIAGRAMS . If fuses are okay, check ECU harness connectors for corrosion or damage. Repair as necessary.
Fig 1: Identifying Driver's Seat ECU Harness Connector Terminals (Pin Side View)
G95E60818Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002