LEXUS LS430 2003 Factory Repair Manual

Fig. 7: >Identifying Terminals Of T9 ECU
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
a. Disconnect the T9 ECU connector.
b. Measure the voltage and resistance of the wire harness side connector.
Standard:
SPECIFIED CONDITION
Symbols (Terminal
No.)
Wiring Color
Terminal
Description
Condition
Specified
Condition
CPUB (T9-1) - GND
(T9-14)V-Y - W-B+B (CPUB) power
supplyAlways10 to 14V
GND (T9-14) - Body
groundW-B - Body
groundGroundAlwaysBelow 1 ohms

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

Fig. 8: Identifying Terminals Of Steering Lock ECU
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
a. Disconnect the S46 ECU connector.
b. Measure the voltage and resistance of the wire harness side connector.
Standard:
SPECIFIED CONDITION
Symbols
(Terminal No.)Wiring
ColorTerminal
DescriptionConditionSpecified Condition
CPUB (S46-1) -
Body groundV-Y - Body
ground+B (CPUB)
Power supplyAlways10 to 14V
+B (S46-10)-
Body groundR-L - Body
ground+B Power supplyAlways10 to 14V
LG-B -1: No key in starter

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

Fig. 10: Identifying Terminals Of DLC3
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
SPECIFIED CONDITION
3.INSPECT BATTERY VOLTAGE Standard: 11 to 14 V
If voltage is below 11 V, recharge the battery before proceeding.
1.DATA LIST
HINT:
Symbols (Terminals No.)Terminal DescriptionConditionSpecified condition
SIL (7) - SG (5)Bus "+" lineDuring transmissionPulse generation
CG (4) - Body groundChassis groundAlwaysBelow 1 ohms
SG (5) - Body groundSignal groundAlwaysBelow 1 ohms
BAT (16) - Body groundBattery positiveAlways11 to 14V

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-

Fig. 14: Wiring Diagram - Driver Door ECU Power Source Circuit
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.INSPECT FUSE (MPX-IG, AM1, D DOOR, MPX-B1, D/C CUT)
a. Remove the MPX-IG and AM1 fuses from the driver side J/B.
b. Remove the D DOOR and MPX-B1 fuses from the passenger side J/B.
c. Remove the D/C CUT fuse from the FL block assy.
d. Measure the resistance.

Standard: Below 1 ohms
NG: REPLACE FUSE
OK: GO TO NEXT STEP
2.INSPECT RELAY (Marking: D-IG1)
a. Remove the D-IG1 relay from the driver side J/B.
b. Measure the resistance.
Standard:
Fig. 15: Identifying terminals Of D
-IG1 Relay
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
SPECIFIED CONDITION
NG: REPLACE RELAY
OK: GO TO NEXT STEP
Tester connectionSpecified condition
3 - 510 kohms or higher
3 - 5Below 1 ohms (when battery voltage is applied to terminals 1 and 2)