Seats - Power W/memory: Other Lexus LS II

MEMORY SYSTEM

Memory system is comprised of power seat ECU. Power seat ECU receives seat position inputs from front vertical, rear vertical, slide and recline sensors within the seat assembly. ECU also receives inputs from memory position recall switches (located on door) and from tilt and telescoping ECU. When a memorized position is recalled, ECU activates the appropriate power seat motors until sensors indicate seat has returned to appropriate memorized position.

SEAT POSITION MEMORY

The memory feature allows the driver to adjust the seat to the desired position (profile), then lock the position into memory. If someone moves the seat, it can be automatically returned by pressing a button. Two profiles can be memorized. The power seat ECU senses the position of the seat by applying a reference voltage to variable resistance sensors.

Before Memorizing Or Activating A Seat Position

Park vehicle. Turn ignition on. Shift transmission into Park. Do not press brakepedal.

Memorizing (Setting) A Seat Position

Move the driver's seat to the desired position. While pressing and holding the SET button (on door panel), press button No. 1 or No. 2. When the beep sounds, release the button (beep indicates that the position has been memorized).

Returning Seat To Memory Position

Turn ignition on. Do not press brake pedal. Press the desired button (No. 1 or No. 2) on the doorpanel.

Note. If key is not in ignition, a memorized seat position can be activated within 30 seconds of opening the driver's door.

Seat Does Not Move In Any Direction

Perform the following tests in order listed until fault is corrected.

1. «+B POWER SOURCE CIRCUIT TEST»(ref-34397-S30707842542001010900000) under SYSTEM TESTING.
2. «POWER SEAT SWITCH CIRCUIT TEST»(ref-34397-S03417672552001010900000) under SYSTEM TESTING.
3. «POWER SEAT MOTOR TEST»(ref-34397-S32839075992001010900000) under COMPONENT TESTING.
4. Check seat motor harness circuits.
5. Replace power seat ECU.

Seat Moves In At Least One Direction

Perform the following tests in order listed until fault is corrected.

1. «POWER SEAT MOTOR TEST»(ref-34397-S32839075992001010900000) under COMPONENT TESTING.
2. Check seat motor harness circuits.
3. Replace power seat ECU.

MANUAL MODE INOPERATIVE, MEMORY RETURN MODE IS OKAY

Perform the following tests in order listed until fault is corrected.

1. «POWER SEAT SWITCH CIRCUIT TEST»(ref-34397-S03417672552001010900000) under SYSTEM TESTING.
2. Replace power seat ECU.

MEMORY FUNCTION DOES NOT OPERATE

Check for problems in power tilt/telescopic steering system. See STEERING COLUMN - POWER TILT SYSTEM article.

DURING RETURN, SEAT DOES NOT STOP WHEN BRAKE PEDAL IS PRESSED

Perform the following tests in order listed until fault is corrected.

1. «STOPLIGHT SWITCH CIRCUIT TEST»(ref-34397-S25554951552001010900000) under SYSTEM TESTING.
2. Replace power seat ECU.

Memory completely Inoperative, Tilt/Telescopic Okay

Perform the following tests in order listed until fault is corrected.

1. «ECU POWER SOURCE CIRCUIT TEST»(ref-34397-S35305087282001010900000) under SYSTEM TESTING.
2. «POSITION SENSOR POWER SOURCE CIRCUIT TEST»(ref-34397-S18996139692001010900000) under SYSTEM TESTING.
3. «SERIAL COMMUNICATION CIRCUIT TEST»(ref-34397-S27993905372001010900000) under SYSTEM TESTING.
4. Replace power seat ECU.

Seat Memory Completely Inoperative, Tilt/Telescopic Steering Memory Inoperative

Check for problems in power tilt/telescopic steering system. See STEERING COLUMN - POWER TILT SYSTEM article.

Perform the following tests in order listed until fault is corrected.

1. «POSITION SENSOR CIRCUIT TEST»(ref-34397-S11290894802001010900000) under SYSTEM TESTING.
2. Replace power seat ECU.

Tilt/Telescopic Steering Okay

Perform the following tests in order listed until fault is corrected.

1. «PARK/NEUTRAL POSITION SWITCH CIRCUIT TEST»(ref-34397-S37598042572001010900000) under SYSTEM TESTING.
2. Replace power seat ECU.

Tilt/Telescopic Steering Inoperative

Perform the following tests in order listed until fault is corrected.

1. «IGNITION SWITCH CIRCUIT TEST»(ref-34397-S21101292662001010900000) under SYSTEM TESTING.
2. Replace power seat ECU.

MEMORY RETURN MODE INOPERATIVE, WHEN KEY IS NOT IN IGNITION ONLY

Check for problems in power tilt/telescopic steering system. See STEERING COLUMN - POWER TILT SYSTEM article.