LEXUS LS430 2003 Factory Repair Manual

d. Check the operation sound of the height control solenoid valve when the solenoid is turned on
through the ACTIVE TEST.
OK:
An operation sound is heard 1 second after the height control solenoid valve is turned on.
NG: Go to step 8
OK: Go to step 9
8.INSPECT HEIGHT CONTROL SOLENOID VALVE
HEIGHT CONTROL SOLENOID VALVE FRONT RH:
a. Disconnect the height control solenoid valve connector.
b. Connect terminal 3 (SLFR) to the battery positive (+) terminal, and terminal 2 (GND) to the battery
negative (-) terminal.
c. Check the operating sound of the height control solenoid valve.
OK:
It should make an operating sound (click).
after turning it ONcan be heard

Fig. 99: Identifying Height Control Solenoid Valve Front RH Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
RESULT DESCRIPTION
HINT:
When a malfunction is found in the front solenoid valve, replace the height control valve sub-assy No. 1.
HEIGHT CONTROL SOLENOID VALVE FRONT LH:
a. Disconnect the height control solenoid valve connector.
b. Connect terminal 1 (SLFL) to the battery positive (+) terminal, and terminal 2 (GND) to the battery
negative (-) terminal.
c. Check the operating sound of the height control solenoid valve.
OK:
It should make an operating sound (click).
OKA
NGB

Fig. 100: Identifying Height Control Solenoid Valve Front LH Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
RESULT DESCRIPTION
HINT:
When a malfunction is found in the front solenoid valve, replace the height control valve sub-assy No. 1.
HEIGHT CONTROL SOLENOID VALVE REAR RH:
a. Disconnect the height control solenoid valve connector.
b. Connect terminal 1 (SLRR) to the battery positive (+) terminal, and terminal 2 (GND) to the battery
negative (-) terminal.
c. Check the operating sound of the height control solenoid valve.
OK:
It should make an operating sound (click).
OKA
NGB

Fig. 101: Identifying Height Control Solenoid Valve Rear RH Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
RESULT DESCRIPTION
HINT:
When a malfunction is found in the rear solenoid valve, replace the height control valve sub-assy No. 2.
HEIGHT CONTROL SOLENOID VALVE REAR LH:
a. Disconnect the height control solenoid valve connector.
b. Connect terminal 3 (SLRL) to the battery positive (+) terminal, and terminal 2 (GND) to the battery
negative (-) terminal.
c. Check the operating sound of the height control solenoid valve.
OK:
It should make an operating sound (click).
OKA
NGC

RESULT DESCRIPTION
HINT:
When a malfunction is found in the rear solenoid valve, replace the height control valve sub-assy No. 2.
B: REPLACE HEIGHT CONTROL VALVE SUB-ASSY NO. 1 (SEE REPLACEMENT
)
C: REPLACE HEIGHT CONTROL VALVE SUB-ASSY NO. 2 (SEE REPLACEMENT
)
A:Go to next step
Fig. 102: Identifying Height Control Solenoid Valve Rear LH Connector Terminals

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
9.INSPECT EXHAUST SOLENOID VALVE
a. Disconnect the exhaust solenoid valve connector.
b. Connect terminal 1 (SLEX) to the battery positive (+) terminal, and terminal 2 (GND) to the battery
ne
gative (-) terminal.
OKA
NGC

c. Check the operating sound of the exhaust solenoid valve.
OK:
It should make an operating sound (click).
HINT:
When a malfunction is found in the exhaust solenoid valve, replace the height control compressor assy.
NG: REPLACE HEIGHT CONTROL COMPRESSOR ASSY (SEE REPLACEMENT
)
OK:Go to next step
Fig. 103: Identifying Exhaust Solenoid Valve Connector Terminals

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

10.INSPECT FOR CLOGGED AIR TUBE
a. Check the air tube visually for a clog or damage (see ON
-VEHICLE INSPECTION ).
OK:
Air tube is not clogged or damaged.
NG: REPAIR OR REPLACE AIR TUBE
OK: REPLACE SUSPENSION CONTROL ECU (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
The signal from the suspension control ECU operates the AIR SUS relay and the height control compressor
motor starts.
The height control compressor motor operates until the targeted vehicle height is reached. Then the height
control sensor sub-assy sends the signal to the suspension control ECU, and stops the height control compressor
motor.
Fig. 104: DTC C1751 And DTC C1752 Detecting Condition And Trouble Area

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.CHECK HEIGHT CONTROL COMPRESSOR CIRCUIT (SEE DTC C1742 HEIGHT
CONTROL COMPRESSOR CIRCUIT )
2.CHECK AIR LEAKAGE (SEE ON
-VEHICLE INSPECTION )
OK:
No leaks

NG: REPAIR OR REPLACE AIR TUBE
OK:Go to next step
3.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
d. Check the operation sound of the height control solenoid valve when the solenoid is turned on
through the ACTIVE TEST.
OK:
An operation sound is heard 1 second after the height control solenoid valve is turned on.
NG: Go to step 4
OK: Go to step 6
4.INSPECT HEIGHT CONTROL SOLENOID VALVE
HEIGHT CONTROL SOLENOID VALVE FRONT RH:
a. Disconnect the height control solenoid valve connector.
b. Connect terminal 3 (SLFR) to the battery positive (+) terminal, and terminal 2 (GND) to the battery
negative (-) terminal.
c. Check the operating sound of the height control solenoid valve.
OK:
It should make an operating sound (click).
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
after turning it ONOperation of solenoid (clicking sound)
can be heard

Fig. 105: Identifying Height Control Solenoid Valve Front RH Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
RESULT DESCRIPTION
HINT:
When a malfunction is found in the front solenoid valve, replace the height control valve sub-assy No. 1.
HEIGHT CONTROL SOLENOID VALVE FRONT LH:
a. Disconnect the height control solenoid valve connector.
b. Connect terminal 1 (SLFL) to the battery positive (+) terminal, and terminal 2 (GND) to the battery
negative (-) terminal.
c. Check the operating sound of the height control solenoid valve.
OK:
It should make an operating sound (click).
OKA
NGB

Fig. 106: Identifying Height Control Solenoid Valve Front LH Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
RESULT DESCRIPTION
HINT:
When a malfunction is found in the front solenoid valve, replace the height control valve sub-assy No. 1.
HEIGHT CONTROL SOLENOID VALVE REAR RH:
a. Disconnect the height control solenoid valve connector.
b. Connect terminal 1 (SLRR) to the battery positive (+) terminal, and terminal 2 (GND) to the battery
negative (-) terminal.
c. Check the operating sound of the height control solenoid valve.
OK:
It should make an operating sound (click).
OKA
NGB