Test J: Position Sensor Circuit

The position sensor senses movement of the seat and sends pulse signals to the power seat control ECU. The ECU uses the number of pulses to constantly calculate the position relative to the memory position and returns seat to the memorized position. If a malfunction occurs in a position sensor and a sensor signal is not input to the ECU, even when the motor operates, the ECU prohibits return operation.

1. Disconnect harness connector from position sensor and motor leading to sensor. Connect battery voltage to terminal No. 3 of sensor connector and ground to terminal No. 2. See Fig 1.
   Fig 1: Identifying Position Sensor & Motor Terminals (Avalon)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. With battery voltage applied to motor connector terminals, measure voltage between ground and sensor connector terminal No. 1. See Fig 1. Check several times with motor in a different position each time. With motor stopped, voltage should be 0-12 volts according to stop position. With motor running, voltage should be 6 volts. If voltage is not as specified, replace sensor. If voltage is as specified, go to next step.
3. Check harness and connectors between power seat control ECU and sensor for poor connections or defects. See WIRING DIAGRAMS . If defects are found, repair as necessary and retest circuit to verify repair. If defects were not found, check and replace power seat control ECU. See TEST D: POWER SEAT CONTROL ECU .