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Ecu Power Source Circuit Test

  1. 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 wiring harness connectors attached.
  2. Measure voltage (backprobe) between 13-pin ECU connector terminals No. 11 (Blue/Red wire) and No. 9 (White/Black wire). See Figure. If battery voltage exists, go to next test listed in SYSTEM TEST INDEX  table. If battery voltage does not exist, go to next step.
  3. Measure resistance (backprobe) between ground and 22-pin ECU connector terminal No. 6 (White/Black wire). Measure resistance (backprobe) between ground and 13-pin ECU connector terminal No. 9 (White/Black wire). If resistance is one ohm or more, repair open ground circuit. If resistance is less than one ohm, go to next step.
  4. Measure voltage (backprobe) between 22-pin ECU connector terminal No. 9 (Purple/Yellow wire) and No. 6 (White/Black wire). If battery voltage exists, go to next test listed in SYSTEM TEST INDEX  table. If battery voltage does not exist, check SEAT-FR (30-amp) fuse and DOME (10-amp) fuse. If fuses are faulty, repair short between fuse and ECU. Replace fuse. If fuses are okay, repair open circuit between fuse(s) and ECU. See WIRING DIAGRAMS .
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