2003 LEXUS LS430 ignition

If the result is not as specified, there may be a malfunction on the wire harness side.
c. Reconnect the T9 ECU connector.
d. Measure the voltage of the connector.
Standard:
SPECIFIED CONDITION
If the result is not as specified, the ECU may have a malfunction.
2.CHECK STEERING LOCK ECU
KSW (T9-3) - GND
(T9-14)LG-B - W-BUnlock warning
switch input1: No key in
ignition key
cylinder --> 2: Key
inserted1: 10 kohms or
higher --> 2:
Below 1 ohms
Symbols
(Terminal No.)Wiring
ColorTerminal
DescriptionConditionSpecified
Condition
KSW (T9-3) - GND
(T9-14)LG-B - W-
BUnlock warning
switch input1: No key in ignition key
cylinder --> 2: Key inserted1: 10 to 14V -->
2:0 V

If the result is not as specified, there may be a malfunction on the wire harness side.
c. Reconnect the S46 ECU connector.
d. Measure the voltage of the connector.
Standard:
SPECIFIED CONDITION
If the result is not as specified, the ECU may have a malfunction.
3.CHECK DRIVER DOOR ECU
Fig. 9: Identifying Terminals Of Driver Door ECU

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
a. Disconnect the D25 ECU connector.
b. Measure the voltage and resistance of the wire harness side connector.
KSW (S46-12) -
Body groundBody
groundUnlock warning
switch inputswitch --> 2: Key
inserted1: 10 kohms or higher
--> 2: Below 1 ohms
PUSH (S46-11)-
Body groundP-B -Body
groundPush switch input
1: No key in starter
switch --> 2: Key
inserted1: 10 kohms or higher
--> 2: Below 1 ohms
GND (S46-9) -
Body groundW-B -Body
groundGroundAlwaysBelow 1ohms
Symbols (Terminal
No.)Wiring
ColorTerminal
DescriptionConditionSpecified
Condition
KSW (S46-12) -
GND (S46-9)LG-B - W-
BUnlock warning
switch input1: No key in ignition cylinder -
-> 2: Key inserted1: 10 to 14V -->
2: 0V
PUSH (S46-11) -
GND (S46-9)P-B - W-BPush switch input1: No key in ignition cylinder -
-> 2: Key inserted1: 10 to 14V -->
2:0V

Standard:
SPECIFIED CONDITION
If the result is not as specified, there may be a malfunction on the wire harness side.
1.DESCRIPTION
Key reminder warning system data can be read in the Data Link Connector 3 (DLC3) of the vehicle.
When the system seems to be malfunctioning, use the hand-held tester to check for malfunctions and
perform repairs.
2.CHECK DLC3
The vehicle's ECU uses the ISO 15765-4 communication protocol. The terminal arrangement of the
DLC3 complies with SAE J1962 and matches the ISO 15765-4 format.
HINT:
Connect the cable of the hand-held tester (with CAN VIM) to the DLC3, turn the ignition switch ON and
attempt to use the hand-held tester. If the screen displays UNABLE TO CONNECT TO VEHICLE, a
problem exists in the vehicle side or the tester side.
If the communication is normal when the tester is connected to another vehicle, inspect the DLC3 on the
original vehicle. If the communication is still impossible when the tester is connected to another vehicle,
the problem is probably in the tester itself. Consult the Service Department listed in the tester's instruction
manual.
Symbols
(Terminal No.)Wiring
ColorTerminal
DescriptionConditionSpecified Condition
CPUB (D25-4) -
Body groundV-Y -Body
ground+B (CPUB) power
supplyAlways10 to 14V
SIG (D25-5) -
Body groundR-L -Body
ground+B (SIG) power
supplyIgnition switch 1: OFF
--> 2: ON1: Below 1 V --> 2: 10 to
14V
BDR (D25-6) -
Body groundR-Body
ground+B (BDR) power
supplyAlways10 to 14V
GND (D25-1) -
Body groundW-B -Body
groundGroundAlwaysBelow 1 ohms
CTY (D25-23) -
Body groundP-G -Body
groundDriver door courtesy
switch inputDriver door 1:
CLOSED --> 2: OPEN1: 10 kohms or higher --
> 2: Below 1 ohms

Using the hand-held tester's DATA LIST allows switch, sensor, actuator and other item values to be read
without removing any parts. Reading the DATA LIST early in troubleshooting is one way to save time.
a. Connect the hand-held tester (with CAN VIM) to the DLC3.
b. Turn the ignition switch ON.
c. Read the DATA LIST on the tester's screen.
Driver door ECU:
Fig. 11: DATA LIST
- Driver Door ECU
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Transponder key ECU (w/o Smart key system):
Fig. 12: DATA LIST
- Transponder Key ECU (w/o Smart Key System)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Steering lock ECU (w/ Smart key system):
Fig. 13: DATA LIST
- Steering Lock ECU (w/ Smart Key System)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
2.ACTIVE TEST
HINT:
Performing the hand-held tester's ACTIVE TEST allows relay, VSV, actuator and other items to be
operated without removin
g any parts. Performing the ACTIVE TEST early in troubleshooting is one way

to save time. The DATA LIST can be displayed during the ACTIVE TEST.
a. Connect the hand-held tester (with CAN VIM) to the DLC3.
b. Turn the ignition switch ON.
c. Perform the ACTIVE TEST according to the display on the tester.
Meter ECU:
ACTIVE TEST - METER ECU
CIRCUIT DESCRIPTION
This circuit supplies power to operate the driver door ECU.
WIRING DIAGRAM
ItemTest DetailsDiagnostic Note
KEY REMINDER BUZZERCombination meter warning buzzer OFF/ON-

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

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
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

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. 60: Displaying Vehicle Moves Erratically
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
8. When the ignition switch is put into the ACC/OFF position on a turn table before parking, the
current vehicle position mark may not point in the correct direction. The same will occur when the
vehicle comes out of parkin
g.