The PTC thermistor's resistance increases when the power seat switch is held down even after the power seat has been moved to the furthest possible position in one direction. If the resistance increases beyond a specified level, the current is shut off to prevent a short circuit.

NOTICE:

The inspection should be performed with the seat installed in the vehicle.

Perform the 4 steps below to check the full range of motion for each power seat function.

Choose a power seat function. Operate the power seat switch and move the seat to the furthest possible position in one direction. Keep the seat in that position for approximately 60 seconds.

Operate the power seat switch again and continue to try to move the seat in the same direction as in the previous step. Measure the time until the current is shut off (motor operation sound will stop).

Standard:
4 to 90 seconds

After the current is shut off, release the power seat switch and wait for approximately 60 seconds.

Operate the same power seat switch and move the seat in the opposite direction. Check that the motor operates.

CHECK LUMBAR SUPPORT ADJUSTER ASSEMBLY

Check the PTC operation inside the power seat motor.

NOTICE:

The inspection should be performed with the seat installed in the vehicle.

Operate the lumbar support switch and move the lumbar support to either the foremost or rearmost position. Keep the seat in that position for approximately 60 seconds.

Operate the lumbar support switch again and continue to try to move the lumbar support in the same direction as in the previous step. Measure the time until the current is shut off (motor operation sound will stop).

Standard:
4 to 90 seconds

After the current is shut off, release the lumbar support switch and wait for approximately 60 seconds.

Operate the lumbar support switch and move the seat in the opposite direction. Check that the motor operates.

CHECK MEMORY AND SEAT RESTORING OPERATION (DRIVER AND FRONT PASSENGER)

A/T:

Turn the engine switch on (IG) and move the shift lever to P.

M/T:

Turn the engine switch on (IG), apply the parking brake, and set the vehicle speed below 3 km/h (1.9 mph).

Move the seat to the foremost and uppermost positions using the seat switch.

Check that the buzzer sounds for 0.5 seconds and the seat position is memorized when the M1 switch is pressed while the SET switch is being pressed.

Move the seat from the foremost and uppermost positions using the seat switch.

Check that the buzzer sounds for 0.5 seconds and the seat position is memorized when the M2 switch is pressed while the SET switch is being pressed.

Move the seat to the rearmost and lowermost positions using the seat switch.

Check that the buzzer sounds for 0.5 seconds and the seat position is memorized when the M3 switch is pressed while the SET switch is being pressed.

Check that the buzzer sounds for 0.1 seconds and the seat automatically moves to the foremost and uppermost positions to the memorized positions when the M1 switch is pressed.

Check that the buzzer sounds for 0.1 seconds and the seat automatically moves out of the maximum front and upper positions (memorized positions) when the M2 switch of the memory switch is pressed.

Check that the buzzer sounds for 0.1 seconds and the seat automatically moves to the rearmost and lowermost positions to the memorized positions when the M3 switch is pressed.

After the engine switch is turned off and the driver side door is opened, check that the buzzer sounds for 0.1 seconds and the seat automatically moves to the memorized position when the M1, M2, or M3 switch is pressed within 30 seconds.

Check that the following procedures erase the memorized seat positions of the M1, M2 and M3 switches: slide the seat fully forward or rearward; hold the M1, M2, or M3 switch; disconnect the cable from the negative (-) battery terminal; and wait for 3 minutes.

HINT:

The seat position will not be stored if the SET switch and 2 or more of the memory switches (for example, M1 and M2) are pressed simultaneously.

CHECK MEMORY CALL FUNCTION (DRIVER SIDE ONLY)

Automatic memory call function check (automatic wireless memory call function)

With a transmitter key recognition code registered:

Perform a wireless door unlock operation and check that opening the driver side door causes the following: 1) the buzzer sounds for 0.1 seconds, and 2) the front seat and the steering wheel (tilt & telescopic), and outer mirror (RH and LH) automatically move to stored positions.

HINT:

The registered transmitter key recognition code is recalled automatically.

If the front seats are not operated, the buzzer will not sound.

Memory registration (transmitter key recognition code registration)

With the engine switch off and the driver side door closed, press and hold the M1, M2, or M3 switch. The front power seat switch (position control ECU) will enter transmitter key recognition code registration mode to allow a key to be linked to seat memory position.

HINT:

If the memory switch is released before entering registration mode, the memory switch will not enter registration mode.

When the transmitter's LOCK or UNLOCK switch is pressed, check that the buzzer of the front power seat switch (position control ECU) sounds once (0.5 seconds).

Memory deletion (transmitter key recognition code memory deletion)

HINT:

If the memory switch is released before entering deletion mode, the memory switch will not enter deletion mode.

When the transmitter's LOCK or UNLOCK switch is pressed, check that the buzzer of the front power seat switch (position control ECU) sounds twice (0.1 seconds each time).

MEMORY CALL EMERGENCY STOP FUNCTION (DRIVER SIDE ONLY)

While a memory call function is operating, check that performing one of the following will stop the memory call operation: 1) press the SET, M1, M2, or M3 switch, or 2) press the front power seat switch (position control ECU).

LEXUS IS250, IS220d / GSE20 ALE20

SEAT

Lexus IS250 IS220d GSE20 ALE20

FRONT POWER SEAT CONTROL SYSTEM w/ Seat Position Memory System