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Parking Brake Switch Circuit Test

NOTE: On manual transmission equipped vehicles, if driver's seat ECU senses parking brake is not applied, it prevents seat from being moved to memorized position.
  1. Start engine. Apply and release parking brake. If parking brake warning light does not come on when parking brake is applied and then go out when it is released, repair warning light circuit before continuing. 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).
  2. Remove driver's seat ECU, but leave wiring harness connectors attached. Measure voltage between chassis ground and terminal No. 15 (Gray wire) of driver's seat ECU connector "A". See Figure.
  3. With parking brake applied, battery voltage should be present. With parking brake released, less than one volt should be present. If voltage is as specified, return to TROUBLE SHOOTING . If voltage is not as specified, repair Black/White wire between driver's seat ECU and parking brake switch. See WIRING DIAGRAMS .
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