DESCRIPTION
WIRING DIAGRAM
INSPECTION PROCEDURE
PERFORM ACTIVE TEST BY INTELLIGENT TESTER (FRONT POWER SEAT SWITCH (POSITION CONTROL ECU))
INSPECT FRONT SEAT ADJUSTER SUB-ASSEMBLY (POWER SEAT MOTOR)
CHECK HARNESS AND CONNECTOR (FRONT POWER SEAT SWITCH - POWER SEAT MOTOR)
FRONT POWER SEAT CONTROL SYSTEM (w/ Seat Position Memory System) - Front Passenger Side Power Seat Motor Circuit
DESCRIPTION
When the power seat control switch is operated, a command signal is sent to the front power seat switch (position control ECU). The front power seat switch (position control ECU) then controls the appropriate seat motor as needed. This memory system does not use a seat position sensor. The seat position is detected by counting pulses that are output when the motor turns. If there is no pulse output from the motor, the motor will stop operating. The front power seat switch (position control ECU) is designed so that any malfunction of the seat memory system will not interfere with manual seat control.
If the front power seat switch (position control ECU) detects a low motor speed, abnormal activity, or sudden motor current fluctuation, the system will stop the motor. If the motor operates continuously for 120 seconds or more, the system will stop the motor until the switch is turned on again.
WIRING DIAGRAM
INSPECTION PROCEDURE
| 1.PERFORM ACTIVE TEST BY INTELLIGENT TESTER (FRONT POWER SEAT SWITCH (POSITION CONTROL ECU)) |
Connect the intelligent tester to the DLC3.
Turn the engine switch on (IG).
Perform the ACTIVE TEST by following the directions on the tester screen.
SEAT:| Item | Test Details | Diagnostic Note |
| Seat Reclining |
Seat reclining operation FRONT / REAR | - |
| Front Vertical Operation |
Seat front vertical operation UP / DOWN | - |
| Lifter Operation |
Seat lifter operation UP / DOWN | - |
| Seat Slide Operation |
Seat sliding operation FRONT / REAR | - |
- OK:
- Each power seat motor operates.
| OK | |
| |
| PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE |
|
| 2.INSPECT FRONT SEAT ADJUSTER SUB-ASSEMBLY (POWER SEAT MOTOR) |
Inspect the power seat motor .
- OK:
- The power seat motor operates.
| | REPLACE FRONT SEAT ADJUSTER SUB-ASSEMBLY (POWER SEAT MOTOR) |
|
|
| 3.CHECK HARNESS AND CONNECTOR (FRONT POWER SEAT SWITCH - POWER SEAT MOTOR) |
LHD
Disconnect the front power seat switch RH (position control ECU) connector and power seat motor connectors.
Measure the resistance according to the value(s) in the table below.
- Standard resistance:
| Tester Connection | Condition | Specified Condition |
| T6-2 (SLD+) - T1-2 | Always | Below 1 Ω |
| T6-3 (SLD-) - T1-1 | Always | Below 1 Ω |
| T6-4 (FRV-) - T4-1 | Always | Below 1 Ω |
| T6-6 (FRV+) - T4-2 | Always | Below 1 Ω |
| T6-7 (LFT+) - T5-1 | Always | Below 1 Ω |
| T6-9 (LFT-) - T5-2 | Always | Below 1 Ω |
| T6-8 (RCL+) - T9-2 | Always | Below 1 Ω |
| T6-10 (RCL-) - T9-1 | Always | Below 1 Ω |
| T6-2 (SLD+) - Body ground | Always | 10 kΩ or higher |
| T6-3 (SLD-) - Body ground | Always | 10 kΩ or higher |
| T6-4 (FRV-) - Body ground | Always | 10 kΩ or higher |
| T6-6 (FRV+) - Body ground | Always | 10 kΩ or higher |
| T6-7 (LFT+) - Body ground | Always | 10 kΩ or higher |
| T6-9 (LFT-) - Body ground | Always | 10 kΩ or higher |
| T6-8 (RCL+) - Body ground | Always | 10 kΩ or higher |
| T6-10 (RCL-) - Body ground | Always | 10 kΩ or higher |
RHD
Disconnect the front power seat switch LH (position control ECU) connector and power seat motor connectors.
Measure the resistance according to the value(s) in the table below.
- Standard resistance:
| Tester Connection | Condition | Specified Condition |
| U6-2 (SLD+) - U2-1 | Always | Below 1 Ω |
| U6-3 (SLD-) - U2-2 | Always | Below 1 Ω |
| U6-4 (FRV-) - U8-2 | Always | Below 1 Ω |
| U6-6 (FRV+) - U8-1 | Always | Below 1 Ω |
| U6-7 (LFT+) - U9-2 | Always | Below 1 Ω |
| U6-9 (LFT-) - U9-1 | Always | Below 1 Ω |
| U6-8 (RCL+) - U5-2 | Always | Below 1 Ω |
| U6-10 (RCL-) - U5-1 | Always | Below 1 Ω |
| U6-2 (SLD+) - Body ground | Always | 10 kΩ or higher |
| U6-3 (SLD-) - Body ground | Always | 10 kΩ or higher |
| U6-4 (FRV-) - Body ground | Always | 10 kΩ or higher |
| U6-6 (FRV+) - Body ground | Always | 10 kΩ or higher |
| U6-7 (LFT+) - Body ground | Always | 10 kΩ or higher |
| U6-9 (LFT-) - Body ground | Always | 10 kΩ or higher |
| U6-8 (RCL+) - Body ground | Always | 10 kΩ or higher |
| U6-10 (RCL-) - Body ground | Always | 10 kΩ or higher |
| | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
| OK | |
| |
| PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE |
|
LEXUS IS250, IS220d / GSE20 ALE20
