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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. Remove power seat ECU, but leave wiring harness connectors attached.
  2. Measure voltage (backprobe) between power seat ECU connector "B" terminals No. 9 (White/Red wire) and No. 11 (Black/Red wire). See Figure. If battery voltage exists, see next test listed in SYSTEM TESTS INDEX  table. If battery voltage does not exist, go to next step.
  3. Measure resistance (backprobe) between power seat ECU connector "B", terminal No. 11 and ground. If resistance is one ohm or more, repair open Black/Red wire (ground circuit). If resistance is less than one ohm, go to next step.
  4. Check ECU-B (10-amp) fuse. If ECU-B fuse is faulty, locate and repair short to ground in Red/White wire between ECU-B fuse and power seat ECU. If fuse is okay, repair open Red/White wire between battery and power seat ECU. See WIRING DIAGRAMS .
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