Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: Power Seat Motor Circuit

Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual / Vehicle Interior / Seat / Rear Power Seat Control System(for Third Row) / Power Seat Motor Circuit

DESCRIPTION

When a switch of the fold seat switch assembly or No. 1 fold seat switch assembly is pushed, the fold seat control ECU receives a switch operation signal and operates each motor.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • When a fold seat control ECU (RH/LH seat) is replaced, it is necessary to perform initialization.

    Click here

  • When No. 2 seat cushion frame sub-assembly RH, No. 2 seat cushion frame sub-assembly LH, No. 2 seatback frame sub-assembly RH or No. 2 seatback frame sub-assembly LH is removed and reinstalled, it is necessary to perform initialization.

    Click here

PROCEDURE

1.

CHECK REAR POWER SEAT CONTROL SYSTEM (for Third Row)

(a) Check that the rear power seat control system (for Third Row) function operates normally.

Result

Proceed to

Lifter motor (RH) does not operate normally.

A

Reclining motor (RH) does not operate normally.

B

Lifter motor (LH) does not operate normally.

C

Reclining motor (LH) does not operate normally.

D
B

GO TO STEP 5

C

GO TO STEP 8

D

GO TO STEP 11

A

2.

INSPECT NO. 2 SEAT CUSHION FRAME SUB-ASSEMBLY RH (LIFTER MOTOR)

(a) Remove the No. 2 seat cushion frame sub-assembly RH.

Click here

(b) Inspect the No. 2 seat cushion frame sub-assembly RH. (Lifter Motor)

Click here

NG

REPLACE NO. 2 SEAT CUSHION FRAME SUB-ASSEMBLY RH

OK

3.

CHECK FOLD SEAT CONTROL ECU (RH SEAT)

(a) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Condition

Specified Condition

x13-4 - Body ground

Fold switch (RH) of fold seat switch assembly or No. 1 fold seat switch assembly pushed

11 to 14 V

x13-3 - Body ground

Return switch (RH) of fold seat switch assembly or No. 1 fold seat switch assembly pushed

11 to 14 V
OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

NG

4.

CHECK HARNESS AND CONNECTOR (FOLD SEAT CONTROL ECU (RH SEAT) - NO. 2 SEAT CUSHION FRAME SUB-ASSEMBLY RH)

(a) Disconnect the x16 fold seat control ECU (RH seat) connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

x16-4 (FLD+) - x13-4

Always

Below 1 Ω

x16-4 (FLD+) or x13-4 - Body ground

Always

10 kΩ or higher

x16-8 (FLD-) - x13-3

Always

Below 1 Ω

x16-8 (FLD-) or x13-3 - Body ground

Always

10 kΩ or higher
OK

REPLACE FOLD SEAT CONTROL ECU (RH SEAT)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

5.

INSPECT NO. 2 SEAT BACKFRAME SUB-ASSEMBLY RH (RECLINING MOTOR)

(a) Remove the No. 2 seatback frame sub-assembly RH.

Click here

(b) Inspect the No. 2 seatback frame sub-assembly RH. (Reclining Motor)

Click here

NG

REPLACE NO. 2 SEATBACK FRAME SUB-ASSEMBLY RH

OK

6.

CHECK FOLD SEAT CONTROL ECU (RH SEAT)

(a) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Condition

Specified Condition

x14-3 - Body ground

Fold switch (RH) of fold seat switch assembly or No. 1 fold seat switch assembly pushed

11 to 14 V

x14-4 - Body ground

Return switch (RH) of fold seat switch assembly or No. 1 fold seat switch assembly pushed

11 to 14 V
OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

NG

7.

CHECK HARNESS AND CONNECTOR (FOLD SEAT CONTROL ECU (RH SEAT) - NO. 2 SEATBACK FRAME SUB-ASSEMBLY RH)

(a) Disconnect the x16 fold seat control ECU (RH seat) connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

x16-3 (RCL+) - x14-3

Always

Below 1 Ω

x16-3 (RCL+) or x14-3 - Body ground

Always

10 kΩ or higher

x16-7 (RCL-) - x14-4

Always

Below 1 Ω

x16-7 (RCL-) or x14-4 - Body ground

Always

10 kΩ or higher
OK

REPLACE FOLD SEAT CONTROL ECU (RH SEAT)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

8.

INSPECT NO. 2 SEAT CUSHION FRAME SUB-ASSEMBLY LH (LIFTER MOTOR)

(a) Remove the No. 2 seat cushion frame sub-assembly LH.

Click here

(b) Inspect the No. 2 seat cushion frame sub-assembly LH. (Lifter Motor)

Click here

NG

REPLACE NO. 2 SEAT CUSHION FRAME SUB-ASSEMBLY LH

OK

9.

CHECK FOLD SEAT CONTROL ECU (LH SEAT)

(a) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Condition

Specified Condition

y13-4 - Body ground

Fold switch (LH) of fold seat switch assembly or No. 1 fold seat switch assembly pushed

11 to 14 V

y13-3 - Body ground

Return switch (LH) of fold seat switch assembly or No. 1 fold seat switch assembly pushed

11 to 14 V
OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

NG

10.

CHECK HARNESS AND CONNECTOR (FOLD SEAT CONTROL ECU (LH SEAT) - NO. 2 SEAT CUSHION FRAME SUB-ASSEMBLY LH)

(a) Disconnect the y16 fold seat control ECU (LH seat) connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

y16-4 (FLD+) - y13-4

Always

Below 1 Ω

y16-4 (FLD+) or y13-4 - Body ground

Always

10 kΩ or higher

y16-8 (FLD-) - y13-3

Always

Below 1 Ω

y16-8 (FLD-) or y13-3 - Body ground

Always

10 kΩ or higher
OK

REPLACE FOLD SEAT CONTROL ECU (LH SEAT)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

11.

INSPECT NO.2 SEATBACK FRAME SUB-ASSEMBLY LH (RECLINING MOTOR)

(a) Remove the No. 2 seatback frame sub-assembly LH.

Click here

(b) Inspect the No. 2 seatback frame sub-assembly LH. (Reclining Motor)

Click here

NG

REPLACE NO.2 SEATBACK FRAME SUB-ASSEMBLY LH

OK

12.

CHECK FOLD SEAT CONTROL ECU (LH SEAT)

(a) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Condition

Specified Condition

y14-3 - Body ground

Fold switch (LH) of fold seat switch assembly or No. 1 fold seat switch assembly pushed

11 to 14 V

y14-4 - Body ground

Return switch (LH) of fold seat switch assembly or No. 1 fold seat switch assembly pushed

11 to 14 V
OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

NG

13.

CHECK HARNESS AND CONNECTOR (FOLD SEAT CONTROL ECU (LH SEAT) - NO. 2 SEATBACK FRAME SUB-ASSEMBLY LH)

(a) Disconnect the y16 fold seat control ECU (LH seat) connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

y16-3 (RCL+) - y14-3

Always

Below 1 Ω

y16-3 (RCL+) or y14-3 - Body ground

Always

10 kΩ or higher

y16-7 (RCL-) - y14-4

Always

Below 1 Ω

y16-7 (RCL-) or y14-4 - Body ground

Always

10 kΩ or higher
OK

REPLACE FOLD SEAT CONTROL ECU (LH SEAT)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
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