LEXUS LS430 2003 Factory Repair Manual

3.CHECK WIRE HARNESS (DRIVER DOOR ECU - BATTERY AND BODY GROUND)
a. Disconnect the D25 ECU connector.
b. Measure the voltage and resistance of the wire harness side connector.
Standard:
Fig. 16: Identifying Terminals Of Driver Door ECU

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SPECIFIED CONDITION
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN ON PROBLEM SYMPTOMS
TABLE
Tester connectionConditionSpecified condition
D25-1 (GND) - Body groundAlwaysBelow 1 ohms
D25-4 (CPUB) - Body groundAlways10 to 14V
D25-6 (BDR)- Body groundAlways10 to 14V
D25-5 (SIG) Body groundIgnition switch ON10 to 14V

CIRCUIT DESCRIPTION
The driver door ECU detects the condition of the front door courtesy lamp switch and sends a switch signal to
the related ECUs via the multiplex communication circuit.
WIRING DIAGRAM
Fig. 17: Wiring Diagram
- Door Courtesy Switch Circuit
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.READ VALUE OF DATA LIST (FRONT DOOR COURTESY LAMP SWITCH)
a. Check the DATA LIST for proper functioning of the door courtesy switch
Multiplex network body ECU (Driver door ECU):

Fig. 18: Multiplex Network Body ECU (Driver Door ECU) Table
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: "ON" (door is open) appears on the screen.
NG: Go to step 2
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN ON PROBLEM SYMPTOMS
TABLE
2.INSPECT FRONT DOOR COURTESY LAMP SWITCH ASSY
a. Remove the courtesy lamp switch.
b. Measure the resistance of the switch.
Standard:
SPECIFIED CONDITION
Tester ConnectionSwitch ConditionSpecified Condition
1 - Body groundNot pushed (ON)Below 1 ohms
1 - Body groundPushed (OFF)10 kohms or higher

Fig. 19: Identifying Terminals Of Front Door Courtesy Lamp Switch Assy
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPLACE FRONT DOOR COURTESY LAMP SWITCH ASSY
OK: GO TO NEXT STEP
3.CHECK WIRE HARNESS (FRONT DOOR COURTESY LAMP SWITCH ASSY LH -
MULTIPLEX NETWORK BODY ECU (DRIVER DOOR ECU))
a. Disconnect the D13 switch and D25 ECU connectors.
b. Measure the resistance of the wire harness side connectors.
Standard:
SPECIFIED CONDITION
Tester connectionSpecified condition
D13-1 - D25-23 (CTY)Below 1 ohms

Fig. 20: Identifying Terminals Of Front Door Courtesy Lamp Switch Assy LH- Multiplex Network
Body ECU
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR

OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN ON PROBLEM SYMPTOMS
TABLE
1.CHECK KEY REMINDER WARNING SYSTEM
a. Check that the key reminder warning buzzer sounds.
1. Close the driver side door, insert the key into the ignition key cylinder and then turn the key
to the LOCK or ACC position.
2. Open the driver side door and check that the buzzer sounds intermittently.
b. Check that the key reminder warning buzzer stops.
1. Check that the buzzer stops sounding if any of the following operations is performed while
the buzzer is sounding:
Close the driver side door (front door courtesy lamp switch is off).
Turn the ignition switch ON.
Pull out the key from the ignition key cylinder.
1.INSPECT UNLOCK WARNING SWITCH ASSY
a. Remove the unlock warning switch.
b. Measure the resistance of the switch.
Standard:
SPECIFIED CONDITION
If the result is not as specified, replace the switch ass
y.
Tester ConnectionSwitch ConditionSpecified Condition
1 -2Not pushed10 kohms or higher
1 -2PushedBelow 1 ohms

Fig. 21: Identifying Terminals Of Unlock Warning Switch Assy
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
2.INSPECT FRONT DOOR COURTESY LAMP SWITCH ASSY (DRIVER SIDE)
a. Remove the courtesy lamp switch.
b. Measure the resistance of the switch.
Standard:

Fig. 22: Identifying Terminals Of Front Door Courtesy Lamp Switch (Driver Side)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
SPECIFIED CONDITION
If the result is not as specified, replace the switch ass
y.
Tester ConnectionSwitch ConditionSpecified Condition
1 - Body groundNot pushed (ON)Below 1 ohms
1 - Body groundPushed (OFF)10 kohms or higher

SYSTEM NAME CHART
System NameSee Procedure
Front Power Seat Control SystemINITIALIZATION

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