Position Sensor Check

POSITION SENSOR CHECK
1. Remove the Power Seat ECU
(a) Remove the driver's seat.
(b) Remove the bolts for the front vertical adjuster and lift the seat cushion up a little.

NOTICE: If the seat cushion is lifted too high, the harness will be pulled and the clamp may come loose.

(c) Remove the Power Seat ECU with the connector attached from where it is installed to the underside of the seat cushion.






2. Position sensor check
(a) Connect terminal CHK of the Power Seat ECU to body ground to put the ECU into check mode.






(b) Measure the voltage between terminal SO of Power Seat ECU and body ground.

HINT: Use an analog type volt meter.






(C) Check that the "ready" code is output as shown in the illustration.






(d) Operate the power seat manual switch and check the change in the voltage when the seat is moving.

HINT: The lumbar support does not have a position sensor, so the sensor check cannot be done.






(e) The changes in the output voltage when the input signal is normal and when it is abnormal are shown in the illustrations. Compare the results with those from (d) and diagnose the condition of each circuit.

HINT:
- The OK and NG codes continue to be output while the manual switch is ON.
- When the seat reaches the limit of movement, e.g. when the headrest reaches the highest or lowest position, the voltage changes from the OK code to the NG code.
After operating any of the system functions with no problem and confirming the OK code and NG code by comparing the amount of wavering of the voltmeter needle, inspect the function with a problem.
- The amount of wavering of the voltmeter needle depends on the meter.