2003 LEXUS LS430 diagram

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS OR / CONNECTOR
OK: REPLACE AIR CONDITIONING AMPLIFIER (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
This is the back-up power source circuit for the A/C amplifier. Power is supplied even when turning the ignition
switch off and is used for diagnostic trouble code memory, etc.
WIRING DIAGRAM
Fig. 146: Back
-Up Power Source Circuit

Fig. 148: Inspecting Air Conditioning Amplifier (B - Body Ground)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS
TABLE
CIRCUIT DESCRIPTION
The main power source is supplied to the A/C amplifier when the ignition switch is turned to the ON position.
The power source supplied is used for operating the A/C amplifier and servomotor, etc.
WIRING DIAGRAM

Fig. 152: Checking Harness And Connector (Air Conditioning Amplifier - Body Ground)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: REPLACE AIR CONDITIONING AMPLIFIER (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
This is the power source for the A/C amplifier and servomotors, etc.
WIRING DIAGRAM

Fig. 156: Identifying Blower Motor Circuit Description
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
WIRING DIAGRAM
Fig. 157: Blower Motor Circuit

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INSPECTION PROCEDURE
1.READ VALUE ON HAND-HELD TESTER
a. Connect the hand-held tester to the DLC3.
b. Turn the ignition switch to the ON position and push the hand-held tester main switch on.
c. Select the item below in the DATA LIST, and read the displa
y on the hand-held tester.

Fig. 164: Identifying Waveform Between Terminal BLW (A11-5) Of A/C Amplifier And Body
Ground
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS
TABLE
CIRCUIT DESCRIPTION
This is the backup power source for the rear A/C amplifier. Power is supplied even when the ignition switch is
off and is used for memory, etc.
WIRING DIAGRAM

Fig. 167: Inspecting Rear Air Conditioning Amplifier (R-B - Body Ground)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS
TABLE
CIRCUIT DESCRIPTION
The main power source is supplied to the A/C amplifier when the ignition switch is turned to the ON position.
The power source supplied is used for operating the A/C amplifier and servomotor, etc.
WIRING DIAGRAM

Fig. 171: Checking Harness And Connector (Rear Air Conditioning Amplifier - Body Ground)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: REPLACE REAR AIR CONDITIONING AMPLIFIER (SEE OVERHAUL
)
CIRCUIT DESCRIPTION
The luggage room J/B ECU requests the rear A/C amplifier to operate the rear blower motor and controls its
operation via the rear blower resistor in this circuit.
WIRING DIAGRAM

Fig. 180: Checking Harness And Connector (Blower Motor -Blower Resistor)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPLACE OR REPLACE HARNESS OR CONNECTOR
REPLACE REAR AIR CONDITIONING AMPLIFIER (SEE OVERHAUL
)
CIRCUIT DESCRIPTION
The exhaust damper control servomotor is controlled by the luggage room J/B ECU and moves the rear exhaust
damper to the desired position.
WIRING DIAGRAM
Fig. 181: Exhaust Damper Control Servomotor Circuit