LEXUS LS430 2003 Factory Repair Manual

Fig. 11: Identifying Terminals Of DLC3
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
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.
TERMINAL DESCRIPTION AND 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:
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 side J/B ECU:
DRIVER SIDE J/B ECU
2.ACTIVE TEST
HINT:
Performing the hand-held tester's ACTIVE TEST allows relay, VSV, actuator and other items to be
operated without removing 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 accordin
g to the display on the tester.
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 14 V
ItemMeasurement
Item/Display (Range)Normal ConditionDiagnostic
Note
FUEL LID
OPN SWFuel lid opener switch
signal /ON or OFFON: Fuel lid opener switch is pushed OFF:
Fuel lid opener switch is not pushed-

Luggage room J/B ECU:
LUGGAGE ROOM J/B ECU
CIRCUIT DESCRIPTION
This circuit provides power to operate the luggage room J/B ECU.
WIRING DIAGRAM
The wirin
g diagram is shown on the next page.
ItemTest DetailsDiagnostic Note
FUEL LID OPENOperate fuel lid opener motor OFF/ON-

Fig. 12: Wiring Diagram - Luggage Room J/B ECU Power Source Circuit
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

INSPECTION PROCEDURE
1.INSPECT FUSE (MPX-B3, MPX-IG and AM1, D/C CUT)
a. Remove the MPX-B3 fuse from the passenger side J/B.
b. Remove the MPX-IG and AM1 fuse from the driver 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.CHECK WIRE HARNESS (LUGGAGE ROOM J/B ECU - BATTERY AND BODY GROUND)
a. Disconnect the LA, LF and LL J/B, and L14 ECU connectors.
b. Measure the resistance and voltage of the wire harness side connectors.
Standard:
TESTER CONNECTION AND SPECIFIED CONDITION
Tester connectionConditionSpecified condition
LF-13 (MPX-IG) - Body groundIgnition switch ON10 to 14 V
LF-12 (MPX-B) - Body groundAlways10 to 14 V
LL-1 (L-O/C (P)) - Body groundAlways10 to 14 V
LA-5 (P-GND) - Body groundAlwaysBelow 1 ohms
L14-5 (SG) - Body groundAlwaysBelow 1 ohms

Fig. 13: Identifying Terminals Of LA, LF, LL J/B And L14 ECU Connectors
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

CIRCUIT DESCRIPTION
The circuit opens the fuel lid when the ECU sends signals to the fuel lid opener switch.
WIRING DIAGRAM
Fig. 14: Wiring Diagram
- Fuel Lid Opener Switch Circuit
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.READ VALUE OF DATA LIST (FUEL LID OPENER SWITCH)
a. Check the DATA LIST for proper functioning of the fuel lid opener switch.
Driver side J/B ECU:

DRIVER SIDE J/B ECU
OK: "ON" (fuel lid opener switch is pulled) appears on the screen.
NG: Go to step 2
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN ON PROBLEM SYMPTOMS
TABLE
2.INSPECT LUGGAGE DOOR OPENING SWITCH ASSY (FUEL LID OPENER SWITCH)
a. Measure the resistance of the switch.
Standard:
TESTER CONNECTION AND SPECIFIED CONDITION
NG: REPLACE LUGGAGE DOOR OPENING SWITCH ASSY
ItemMeasurement
Item/Display (Range)Normal ConditionDiagnostic
Note
FUEL LID
OPN SWFuel lid opener switch
signal /ON or OFFON: Fuel lid opener switch is pulled OFF:
Fuel lid opener switch is not pulled-
Tester ConnectionSwitch ConditionSpecified Condition
A-1 - A-2OFF (not pulled)10 kohms or higher
A-1 - A-2ON (pulled)Below 1 ohms

Fig. 15: >Identifying Terminals Of Fuel Lid Opener Switch
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: GO TO NEXT STEP

3.CHECK WIRE HARNESS (DRIVER SIDE J/B ECU - FUEL LID OPENER SWITCH AND
BODY GROUND)
a. Disconnect the D6 ECU connector.
b. Disconnect the F12 switch connector.
c. Measure the resistance of the wire harness side connectors.
Standard:
TESTER CONNECTION AND SPECIFIED CONDITION
Tester connectionSpecified condition
D6-4 (FUEL) - F12-2Below 1 ohms
F12-1 - Body groundBelow 1 ohms