2003 LEXUS LS430 fuses

Fig. 42: Driver Door ECU Power Source Circuit - Wiring Diagram
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

1.INSPECT FUSE (MPX-IG, AM1, P DOOR, MPX-B1, D/C CUT)
a. Remove the MPX-IG and AM1 fuses from the driver side J/B.
b. Remove the P 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.
Fig. 46: Inspecting Relay (D
- IG1)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
TERMINALS RESISTANCE REFERENCE
Terminal No.Specified Condition
3 - 510 kohms or higher

Fig. 48: Rear Door LH ECU Power Source Circuit - Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.INSPECT FUSE (MPX-IG, AM1, RR DOOR LH, MPX-B1, D/C CUT)
a. Remove the MPX-IG and AM1 fuses from the driver side J/B.

b. Remove the RR DOOR LH 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.
TERMINALS RESISTANCE REFERENCE
Fig. 49: Inspecting Relay (D
-IG1)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPLACE RELAY
Terminal No.Specified Condition
3 - 510 kohms or higher
3 - 5Below 1 ohms (when battery voltage is applied to terminals 1 and 2)

Fig. 51: Rear Door RH ECU Power Source Circuit -Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.INSPECT FUSE (MPX-IG, AM1, RR DOOR RH, MPX-B1, D/C CUT)
a. Remove the MPX-IG and AM1 fuses from the driver side J/B.
b. Remove the MPX-B1 and RR DOOR RH 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.
Fig. 52: Inspecting Relay (D
-IG1)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.INSPECT FUSE (MPX-B1, AM2, STR LOCK, D/C CUT)
a. Remove the MPX-B1, AM2 and STR LOCK fuses from the passenger side J/B.
b. Remove the D/C CUT fuse from the FL block.
c. Measure the resistance of the fuse.
Standard: Below 1 ohms
NG: REPLACE FUSE
OK: Go to next step
2.CHECK WIRE HARNESS (STEERING LOCK ECU - BATTERY AND BODY GROUND)
a. Disconnect the S46 ECU connector.
b. Measure the resistance and voltage of the wire harness side connector.
Standard:
STEERING LOCK ECU - BATTERY AND BODY GROUND - RESISTANCE TABLE
Tester connectionConditionSpecified condition
S46-1 (CPUB) - Body groundAlways10 to 14 V
S46-2 (IG2) - Body groundIgnition switch OFF -> ON0 V -> 10 to 14 V
S46-10 (+B) - Body groundAlways10 to 14 V
S46-9 (GND) - Body groundAlwaysBelow 1 ohms

Fig. 45: ECU Power Source Circuit - Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.INSPECT FUSE (MPX-B1, AM2, D/C CUT)
a. Remove the MPX-B1 and AM2 fuses from the passenger side J/B.
b. Remove the D/C CUT fuse from the FL block.
c. Measure the resistance of the fuse.
Standard: Below 1ohms
NG: REPLACE FUSE
OK: Go to next step

INSPECTION PROCEDURE
1.INSPECT FUSE (D/C CUT, D P/SEAT, MPX-IG, AM1, MPX-B1)
a. Remove the D/C CUT fuse from the FL block.
b. Remove the D P/SEAT, MPX-IG and AM1 fuses from the driver side J/B.
c. Remove the MPX-B1 fuse from the passenger side J/B.
d. Measure the resistance of the fuse.
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 of the relay.
Standard:
TESTER CONNECTION AND SPECIFIED CONDITION
Tester connectionSpecified condition
3 - 510 kohms or higher
3 - 5Below 1 ohms (when battery voltage is applied to terminals 1 and 2)