LEXUS LS430 2003 Factory Repair Manual

Fig. 89: Identifying Fusible Link Block Side Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK:Go to next step
5.CHECK HARNESS AND CONNECTOR (AIR SUS RELAY - BODY GROUND) (SEE
ELECTRONIC CIRCUIT INSPECTION PROCEDURE
)
a. Measure the resistance according to the value (s) in the table below.
TESTER CONNECTION STANDARD SPECIFIED CONDITION
Tester ConnectionSpecified Condition
4 (for AIR SUS relay) - Body groundBelow 1 ohms

Fig. 90: Identifying Air Sus Relay Location
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: REPLACE SUSPENSION CONTROL ECU (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
The signal from the suspension control ECU turns on the AIR SUS relay. At that time, battery voltage is input
to the height control compressor motor through the AIR SUS relay. The height control compressor motor starts.
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Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
WIRING DIAGRAM
Fig. 92: Height Control Compressor Wiring Diagram

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.RECONFIRM DTC
a. Check DTCs (SEE DTC CHECK/CLEAR
).
1. Confirm if DTC C1741 is recorded.
OK:
DTC C1741 is not output.

HINT:
If DTC C1741 (AIR SUS relay circuit) is displayed, carry out the inspection necessary (SEE DTC C1741
AIR SUS RELAY CIRCUIT ).
NG: REPAIR CIRCUIT INDICATED BY OUTPUT CODE
OK:Go to next step
2.INSPECT HEIGHT CONTROL COMPRESSOR MOTOR
a. Disconnect the height control compressor motor connector.
b. Connect terminal 1 (B) to the battery positive (+) terminal, and terminal 2 (E) to the battery
negative (-) terminal.
c. Check the operating sound of the compressor motor.
OK:
Compressor motor operates.
HINT:
When a malfunction is found in the height control compressor motor, replace the height control
compressor assy.
NG: REPLACE HEIGHT CONTROL COMPRESSOR ASSY (SEE REPLACEMENT
)
OK:Go to next step

Fig. 93: Identifying Height Control Compressor Motor Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
3.CHECK HARNESS AND CONNECTOR (SUSPENSION CONTROL ECU - HEIGHT
CONTROL COMPRESSOR MOTOR) (SEE ELECTRONIC CIRCUIT INSPECTION
PROCEDURE )
a. Connect the height control compressor motor connector.
b. Disconnect the suspension control ECU A21 connector.
c. Measure the resistance according to the value (s) in the table below.
TESTER CONNECTION STANDARD SPECIFIED CONDITION
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
Tester ConnectionSpecified Condition
A21-17 (RM+) - A21-18 (RM-)6.4 to 7.4 ohms

Fig. 94: Identifying Suspension Control ECU Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK:Go to next step
4.CHECK HARNESS AND CONNECTOR (HEIGHT CONTROL COMPRESSOR MOTOR -
BODY GROUND) (SEE ELECTRONIC CIRCUIT INSPECTION PROCEDURE
)
a. Measure the resistance according to the value (s) in the table below.
TESTER CONNECTION STANDARD SPECIFIED CONDITION
Tester ConnectionSpecified Condition
H11-2 (E) - Body groundBelow 1 ohms

Fig. 95: Identifying Height Control Compressor Motor Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK:Go to next step
5.CHECK HARNESS AND CONNECTOR (HEIGHT CONTROL COMPRESSOR MOTOR - AIR
SUS RELAY) (SEE ELECTRONIC CIRCUIT INSPECTION PROCEDURE
)
a. Disconnect the AIR SUS relay from the fusible link block.
b. Measure the resistance according to the value (s) in the table below.
TESTER CONNECTION STANDARD SPECIFIED CONDITION
Tester ConnectionSpecified Condition
1 (B) - 2 (for AIR SUS relay)Below 1 ohms
1 (B) - Body ground10 Kohms or higher

Fig. 96: Identifying Height Control Compressor Motor Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

Fig. 97: Identifying Air Sus Relay Location
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK:Go to next step
6.CHECK HARNESS AND CONNECTOR (AIR SUS RELAY - BODY GROUND) (SEE
ELECTRONIC CIRCUIT INSPECTION PROCEDURE
)
a. Measure the voltage according to the value (s) in the table below.
TESTER CONNECTION STANDARD SPECIFIED CONDITION
Tester ConnectionSpecified Condition
4 (for AIR SUS relay) - Body ground10 to 14 V

Fig. 98: Identifying Air Sus Relay Location
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK:Go to next step
7.INSPECT HEIGHT CONTROL SOLENOID VALVE
a. Connect the hand-held tester to the DLC3.
b. Turn the ignition switch to the ON position and turn the hand-held tester main switch on.
c. Select the item below in the ACTIVE TEST and operate it with the hand-held tester.
VEHICLE CONDITION / TEST DETAILS AIRSUS
ItemVehicle Condition / Test DetailsDiagnostic Note
FR SOLTurn OFF right front solenoid valve one second
after turning it ONOperation of solenoid (clicking sound)
can be heard
FL SOLTurn OFF left front solenoid valve one second
after turning it ONOperation of solenoid (clicking sound)
can be heard
RR SOLTurn OFF right rear solenoid valve one second
after turning it ONOperation of solenoid (clicking sound)
can be heard
RL SOLTurn OFF left rear solenoid valve one second Operation of solenoid (clicking sound)