LEXUS LS430 2003 Factory Repair Manual

Lower side control
TESTER CONNECTION AND SPECIFIED CONDITION
Tester ConnectionSwitch ConditionSpecified Condition
5 (B) - 1 (H)HOLDBelow 1 ohms
4 (R) - 6 (E)HOLDBelow 1 ohms
1 (H) - 6 (E)OFFBelow 1 ohms
4 (R) - 6 (E)OFFBelow 1 ohms
1 (H) - 6 (E)RELEASEBelow 1 ohms
4 (R) - 5 (B)RELEASEBelow 1 ohms
Tester ConnectionSwitch ConditionSpecified Condition
2 (H1) - 5 (B)HOLDBelow 1 ohms
3 (R1) - 6 (E)HOLDBelow 1 ohms
2 (H1) - 6 (E)OFFBelow 1 ohms
3 (R1) - 6 (E)OFFBelow 1 ohms
2 (H1) - 6 (E)RELEASEBelow 1 ohms
3 (R1) - 5 (B)RELEASEBelow 1 ohms

Fig. 29: Identifying Lumbar Support Switch Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPLACE LUMBAR SUPPORT SWITCH
OK: GO TO NEXT STEP
2.INSPECT POWER SEAT MOTOR (SEE INSPECTION
)
NG: REPLACE POWER SEAT MOTOR
OK: GO TO NEXT STEP
3.CHECK WIRE HARNESS (LUMBAR SUPPORT SWITCH - POWER SEAT MOTOR AND
BODY GROUND)
a. Disconnect the P23 switch, connector.
b. Disconnect the P30 and P31 motor connectors.
c. Measure the resistance and voltage of the wire harness side connectors.
Standard:
TESTER CONNECTION AND SPECIFIED CONDITION
Tester connectionSpecified condition
P23-1 (H) - P31-1Below 1 ohms
P23-4 (R) - P31-2Below 1 ohms
P23-2 (H1) - P30-2Below 1 ohms
P23-3 (R1) - P30-1Below 1 ohms
P23-6 (E) - Body groundBelow 1 ohms
P23-5 (B) - P23-6 (E)10 to 14 V

Fig. 30: Identifying P23 Lumbar Support Switch Connector Terminals And P30,P31 Power Seat
Motor Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR AND REPLACE HARNESS AND CONNECTOR

OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN ON PROBLEM SYMPTOMS
TABLE
CIRCUIT DESCRIPTION
Pressing the seat cushion switch activates the seat cushion motor.
WIRING DIAGRAM
Fig. 31: Power Seat Cushion Switch Wiring Diagram

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.INSPECT POWER SEAT CUSHION SWITCH
a. Remove the power seat cushion switch.
b. Measure the resistance of the switch.
Standard:
TESTER CONNECTION AND SPECIFIED CONDITION

Tester ConnectionSwitch ConditionSpecified Condition
1 (CSNF) - 4 (E)FRONTBelow 1 ohms
1 (CSNF) - 4 (E), 2 (CSNR) - 4 (E)OFF10 kohms or higher
2 (CSNR) - 4 (E)REARBelow 1 ohms

Fig. 32: Identifying Power Seat Cushion Switch Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPLACE POWER SEAT CUSHION SWITCH
OK: GO TO NEXT STEP
2.CHECK WIRE HARNESS (POWER SEAT CONTROL SWITCH - DRIVER SEAT ECU AND
BODY GROUND)
a. Disconnect D28 ECU and P22 switch connectors.
b. Measure the resistance of the wire harness side connectors.
Standard:
TESTER CONNECTION AND SPECIFIED CONDITION
Tester connectionSpecified condition
D28-4 (CSNR) - P22-2 (CSNR)Below 1 ohms
D28-12 (CSNF) - P22-1 (CSNF)Below 1 ohms
P22-4 (E) - Body groundBelow 1 ohms

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03002600520051005100480046005700520055000300370048[rminals And D28 Driver Seat
ECU Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR AND REPLACE HARNESS AND CONNECTOR

OK:
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN ON PROBLEM SYMPTOMS TABLE

CIRCUIT DESCRIPTION
The driver door ECU detects the condition of the driving memory switch, and sends the information to the
power seat ECU and the tilt and telescopic ECU via the multiplex communication circuit.
WIRING DIAGRAM
Fig. 34: Driving Position Memory Switch (W/ Memory) Wiring Diagram

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.READ VALUE OF HAND-HELD TESTER
a. Connect the hand-held tester (with CAN VIM) to the DLC3.
b. Turn the ignition switch ON and press the hand-held tester main switch ON.
c. Select the items below in the DATA LIST, and read the displa
ys on the hand-held tester.