2003 LEXUS LS430 fuse

Fig. 158: Identifying Location Of Fuse (Heater)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: Go to next step
5.CHECK HARNESS AND CONNECTOR (BLOWER MOTOR - AIR CONDITIONING
AMPLIFIER) (SEE ELECTRONIC CIRCUIT INSPECTION PROCEDURE
)
a. Measure the resistance according to the value (s) in the table below.
Standard:
BLOWER MOTOR - AIR CONDITIONING AMPLIFIER RESISTANCE
Tester connectionConditionSpecified condition
A11-5 (BLW) -B2-2 (SI)AlwaysBelow 1 ohms
A11-5 (BLW) - Body groundAlways10 kohms or higher

Fig. 165: Rear Back-Up Power Source Circuit
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.INSPECT FUSE (RR ECU-B)
a. Remove RR ECU-B fuse from luggage room J/B.
b. Measure the resistance according to the value (s) in the table below.
Standard:
FUSE (RR ECU-B) RESISTANCE
Tester itemConditionSpecified condition
RR ECU-BAlwaysBelow 1 ohms

Fig. 166: Identifying Location Of Fuse (RR ECU-B)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: CHECK FOR SHORT IN ALL HARNESSES AND COMPONENTS CONNECTED TO
FAILURE FUSE (RR ECU-B)
OK: Go to next step
2.INSPECT REAR AIR CONDITIONING AMPLIFIER (R-B - BODY GROUND)
a. Remove the rear A/C amplifier assy and disconnect the connector.
b. Measure the voltage according to the value (s) in the table below.
Standard:
REAR AIR CONDITIONING AMPLIFIER (R-B - BODY GROUND) VOLTAGE
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (REAR AIR CONDITIONING
AMPLIFIER -BATTERY)
Tester connectionConditionSpecified condition
A46-3 (R-B) - Body groundAlways10 to 14 V

Fig. 168: Rear 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 (RR A/C)
a. Remove the RR A/C fuse from the luggage room J/B.
b. Measure the resistance according to the value (s) in the table below.
Standard:

FUSE (RR A/C) RESISTANCE
NG: CHECK FOR SHORT IN ALL HARNESS AND COMPONENTS CONNECTED TO
FAILURE FUSE (RR A/C FUSE)
OK: Go to next step
2.INSPECT REAR 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:
REAR AIR CONDITIONING AMPLIFIER (IG - GND) VOLTAGE
NG: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS
TABLE
Tester itemConditionSpecified condition
RR A/C fuseAlwaysBelow 1 ohms
Tester connectionConditionSpecified condition
A46-10 (IG) -A46-6 (GND)Ignition switch OFF --> ONBelow 1 V --> 10 to 14 V

NORMAL CONDITION AIRSUS
d. Check the voltage
Standard:
10 to 14 V
NG: Go to step 5
OK:Go to next step
2.CHECK SOURCE VOLTAGE
a. Check the battery voltage.
Standard:
11 to 14 V
NG: REPLACE BATTERY
OK:Go to next step
3.INSPECT FUSE (AM1)
a. Remove the AM1 fuse from the driver side J/B.
b. Check fuse.
1. Check continuity of the AM1 fuse.
Standard:
Continuity
ItemNormal Condition
IG VOLTAGEActual ECU power supply voltage 10 to 14 V

Fig. 116: Identifying AM1 Fuse Location
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: CHECK FOR SHORT IN ALL HARNESS AND CONNECTOR CONNECTED TO FUSE
AND REPLACE FUSE
OK:Go to next step
4.INSPECT FUSE (AIR SUS)
a. Remove the AIRSUS fuse from the driver side J/B.
b. Check fuse.
1. Check continuity of the AIRSUS fuse.
Standard:
Continuity

Fig. 117: Identifying Air sus Fuse Location
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: CHECK FOR SHORT IN ALL HARNESS AND CONNECTOR CONNECTED TO FUSE
AND REPLACE FUSE