2003 LEXUS LS430 fuse

Fig. 90: Identifying ABS-IG Fuse Location
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: INSPECT FOR SHORT CIRCUIT IN ALL HARNESS AND COMPONENTS CONNECTED
TO ECU-IG FUSE

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.INSPECT RADIO AND RECEIVER ASSY
a. Turn the ignition switch to the ON position.
b. Turn the radio and receiver assy on.
c. Set the radio channels and register them.
d. Turn the ignition switch off.
e. Turn the ignition switch to the ON position.
f. Turn the radio and receiver assy on.
g. Check if the registered memory is deleted or not.
OK:
The registered memory is not deleted.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (DRIVER SIDE J/B - BATTERY)
OK: Go to next step
2.INSPECT FUSE (A/C)
a. Remove the A/C fuse from the driver side J/B.
b. Measure the resistance according to the value (s) in the table below.
Standard:
FUSE (A/C) RESISTANCE
NG: CHECK FOR SHORT IN ALL HARNESSES AND COMPONENTS CONNECTED TO
FAILURE FUSE
Tester itemConditionSpecified condition
A/C fuseAlwaysBelow 1 ohms

Fig. 147: Identifying Location Of Fuse (A/C)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: Go to next step
3.INSPECT AIR CONDITIONING AMPLIFIER (B - BODY GROUND)
a. Remove the A/C amplifier assy and disconnect the connector.
b. Measure the voltage according to the value (s) in the table below.
Standard:
AIR CONDITIONING AMPLIFIER (B - BODY GROUND) VOLTAGE
NG: REPAIR OR REPLACE WIRE HARNESS (AIR CONDITIONING AMPLIFIER -
BATTERY)
Tester connectionConditionSpecified condition
A11-21 (+B) - Body groundAlways10 to 14 V

Fig. 149: IG Power Source Circuit
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
HINT:
Start the engine before inspection. Check the IG1 relay or battery if the engine does not start.
1.INSPECT FUSE (P-IG)
a. Remove the P-IG fuse from the passenger side J/B.
b. Measure the resistance according to the value (s) in the table below.
Standard:

FUSE (P-IG) RESISTANCE
NG: CHECK FOR SHORT IN ALL HARNESSES AND COMPONENTS CONNECTED TO
FAILURE FUSE
OK: Go to next step
2.INSPECT AIR CONDITIONING AMPLIFIER (IG - GND)
a. Remove the A/C amplifier assy with connectors still connected.
b. Turn the ignition switch to the ON position.
c. Measure the voltage according to the value (s) in the table below.
Standard:
AIR CONDITIONING AMPLIFIER (IG - GND) VOLTAGE
NG: Go to STEP 3
Tester itemConditionSpecified condition
P-IG fuseAlwaysBelow 1 ohms
Tester connectionConditionSpecified condition
A11-9 (IG) - 14-1 (GND)Ignition switch ON10 to 14V

Fig. 154: Inspecting Air Conditioning Amplifier (ACC - Body Ground)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS
TABLE
2.INSPECT FUSE (P-ACC)
a. Remove the P-ACC fuse from the passenger side J/B.
b. Measure the resistance according to the value (s) in the table below.
Standard:
FUSE (P-ACC) RESISTANCE
NG: CHECK FOR SHORT IN ALL HARNESSES AND COMPONENTS CONNECTED TO
FAILURE FUSE
Tester itemConditionSpecified condition
P-ACC fuseAlwaysBelow 1 ohms

Fig. 155: Identifying Location Of Fuse (P-ACC)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: REPAIR OR REPLACE HARNESS OR CONNECTOR (AIR CONDITIONING
AMPLIFIER - BATTERY)
CIRCUIT DESCRIPTION
The blower motor is operated by signals from the A/C amplifier assy. Blower motor speed signals are
transmitted by changes in the duty ratio.
Duty Ratio
The duty ratio is the ratio of the period of continuity in one cycle. For example, if A is the period of continuity
in one cycle, B is the period of non-continuity.
The blower motor controller controls the blower motor speed.

b. Turn the radio and receiver assy on.
c. Set the radio channels and register them.
d. Turn the ignition switch off.
e. Turn the ignition switch to the ON position.
f. Turn the radio and receiver assy on.
g. Check if the registered memory is deleted or not.
OK:
The registered memory is not deleted.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (DRIVER SIDE J/B - BATTERY)
OK: Go to next step
4.INSPECT FUSE (HEATER)
a. Remove the HEATER fuse from the FL block.
b. Measure the resistance according to the value (s) in the table below.
Standard:
FUSE (HEATER) RESISTANCE
NG: CHECK FOR SHORT IN ALL HARNESSES AND COMPONENTS CONNECTED TO
FAILURE FUSE
Tester itemConditionSpecified condition
HEATER fuseAlwaysBelow 1 ohms