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Ecu Power Source Circuit Test

NOTE: Use this procedure to check for problems in circuit between DOME fuse and power seat ECU.
  1. At driver's seat, remove bolts for front vertical adjuster. Lift front end of seat cushion slightly for access to driver's seat ECU (do not lift too far; harness clamp may come loose). Remove driver's seat ECU, leaving wiring harness connectors attached.
  2. Measure voltage (backprobe) between terminals No. 7 (Red wire) and 18 (Blue/Red wire) at drivers seat ECU connector "B". See Figure. If battery voltage is present, return to TROUBLE SHOOTING .
  3. If battery voltage is not present, measure resistance between ground and driver's seat ECU, connector "B", terminal No. 18. If resistance is one ohm or more, repair open on Blue/Red wire ground circuit. If resistance is less than one ohm, check DOME (10-amp) fuse, located in relay block No. 2 in engine compartment.
  4. If DOME fuse is blown, locate and repair short to ground on Red wire between DOME fuse and driver's seat ECU. If fuse is okay, repair Red wire between battery and driver's seat ECU. See WIRING DIAGRAMS .
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