Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual: Power Seat Power Easy Access System Function does not Operate

Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual / Vehicle Interior / Seat / Front Power Seat Control System (w/ Memory) / Power Seat Power Easy Access System Function does not Operate

DESCRIPTION

  • The seat slides backward when either of the following conditions is met:
    • The driver seat belt is unfastened with the engine switch off and the shift lever in P.
    • The engine switch is turned from on (IG) or on (ACC) to off with the shift lever in P and the driver seat belt unfastened.
  • The seat slides forward when either of the following conditions is met:
    • The driver seat belt is fastened with the engine switch on (IG) or on (ACC) and the shift lever in P or N.
    • The engine switch is turned from off to on (IG) or on (ACC) with the shift lever in P and the driver seat belt unfastened.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • The front power seat control system (w/ Memory) uses the CAN communication system. First, confirm that there are no malfunctions in the CAN communication system. Refer to How to Proceed with Troubleshooting.

    Click here

  • Before replacing the main body ECU (multiplex network body ECU), refer to Registration.
  • Inspect the fuses for circuits related to this system before performing the following procedure.

PROCEDURE

1.

CHECK FRONT POWER SEAT OPERATION

(a) Check that each function of the power seat operates normally by using the position control ECU and switch assembly LH.

Click here

Result

Proceed to

Power seat functions operate normally

A

All power seat functions do not operate

B

One or more power seat motors do not operate

C
B

GO TO OTHER DIAGNOSTIC PROCEDURE (Front Power Seat does not Operate with Front Power Seat Switch)

C

GO TO OTHER DIAGNOSTIC PROCEDURE (One or more Power Seat Motors do not Operate)

A

2.

READ VALUE USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Driver Seat / Data List.

(e) Read the Data List according to the display on the Techstream.

Body Electrical > Driver Seat > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

Driver Seat Buckle SW

Driver seat belt buckle switch

ON or OFF

ON: Driver seat belt fastened

OFF: Driver seat belt unfastened

-
Body Electrical > Driver Seat > Data List

Tester Display

Driver Seat Buckle SW

OK:

On the Techstream screen, ON or OFF is displayed accordingly.

NG

GO TO STEP 8

OK

3.

CHECK HARNESS AND CONNECTOR (FRONT SEAT OUTER BELT ASSEMBLY LH - IG POWER SUPPLY)

(a) Disconnect the S2 front seat outer belt assembly LH connector.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

S2-1 (IG) - Body ground

Engine switch on (IG)

11 to 14 V

S2-1 (IG) - Body ground

Engine switch off

Below 1 V
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

4.

CHECK HARNESS AND CONNECTOR (FRONT SEAT OUTER BELT ASSEMBLY LH - POSITION CONTROL ECU AND SWITCH ASSEMBLY LH)

(a) Disconnect the c6 position control ECU and switch assembly LH connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

S2-2 (L) - c6-9 (RDC)

Always

Below 1 Ω

S2-2 (L) or c6-9 (RDC) - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

5.

CHECK SEAT BELT TENSION REDUCER SYSTEM

(a) Check the seat belt tension reducer system.

Click here

OK:

Seat belt tension reducer system is normal.

NG

REPLACE FRONT SEAT OUTER BELT ASSEMBLY LH

OK

6.

REPLACE POSITION CONTROL ECU AND SWITCH ASSEMBLY LH

(a) Replace the position control ECU and switch assembly LH with a new or known good one.

Click here

NEXT

7.

CHECK POWER SEAT POWER EASY ACCESS SYSTEM

(a) Check the power seat easy access system.

Click here

OK:

Power seat power easy access system is normal.

OK

END (POSITION CONTROL ECU AND SWITCH ASSEMBLY LH WAS DEFECTIVE)
NG

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

8.

INSPECT FRONT SEAT INNER BELT ASSEMBLY LH

(a) Remove the front seat inner belt assembly LH.

Click here

(b) Inspect the front seat inner belt assembly LH.

Click here

NG

REPLACE FRONT SEAT INNER BELT ASSEMBLY LH

OK

9.

CHECK HARNESS AND CONNECTOR (POSITION CONTROL ECU AND SWITCH ASSEMBLY LH - FRONT SEAT INNER BELT ASSEMBLY LH)

(a) Disconnect the c6 position control ECU and switch assembly LH connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

c6-10 (DBCL) - c11-1 (RDC)

Always

Below 1 Ω

c6-10 (DBCL) or c11-1 (RDC) - Body ground

Always

10 kΩ or higher
OK

REPLACE POSITION CONTROL ECU AND SWITCH ASSEMBLY LH

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
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