2003 LEXUS LS430 shock absorber

a. The suspension control ECU operates the compressor & motor with the dryer and uses the solenoid
valves to control the vehicle height by analyzing the information based on the switches, sensors and
input signals.
b. Through the 4 height control sensors, the suspension control ECU detects the changes in the vehicle
height that results from the number of occupants or the amount of the load. Then, the suspension
control ECU controls the height control solenoid valves and the compressor & motor with the dryer
in order to automatically adjust the vehicle height to a constant (normal) level.
c. Furthermore, two vehicle heights can be selected by operating the height control switch: HI and
Normal.
d. In cases such as when the vehicle is jacked up, the auto leveling function is prohibited by turning
the ignition switch off.
If the vehicle is raised with its engine running, connect terminals OPB and CG of the DLC3 so the
vehicle height control is not carried out.
e. The absorber control switch selects the shock absorber damping force (normal or sport).
f. w/ Pre-collision safety system:
The suspension control ECU changes the stiffness of the suspension to the hardest setting by
receiving signals (collision unavoidable) from the cruise control ECU.
Function of Components

a. Connect the hand-held tester to the DLC3.
b. Turn the ignition switch to the ON position.
c. Following the display on the hand-held tester, perform the "ACTIVE TEST".
VEHICLE CONDITION / TEST DETAILS
HINT:
If an abnormality is not found when the parts are inspected, inspect the suspension control ECU.
If a trouble code is displayed during the DTC check, check the circuit listed for that code.
DIAGNOSTIC TROUBLE CODE CHART
ItemVehicle Condition / Test DetailsDiagnostic Note
DAMPER FRChanges damper step (Front Right) / min.: 1
step, max.: 17 stepShock absorber hardens as
damper step increases
DAMPER FLChanges damper step (Front Left) / min.: 1
step, max.: 17 stepShock absorber hardens as
damper step increases
DAMPER RRChanges damper step (Rear Right) / min.: 1
step, max.: 17 stepShock absorber hardens as
damper step increases
DAMPER RLChanges damper step (Rear Left) / min.: 1 step,
max.: 17 stepShock absorber hardens as
damper step increases
FR UP &
DOWNRight front vehicle height / UP or DOWN-
FL UP & DOWNLeft front vehicle height / UP or DOWN-
RR UP &
DOWNRight rear vehicle height / UP or DOWN-
RL UP &
DOWNLeft rear vehicle height / UP or DOWN-
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
MOTOR
RELAYAIR SUS relay / ON or OFFOperation of solenoid (clicking
sound) can be heard
DTCDescription
DTC C1711, DTC C1712, DTC C1713,
DTC C1714, DTC C1714
RIGHT FRONT HEIGHT CONTROL SENSOR
CIRCUIT

Fig. 133: Identifying Height Control Switch Connector Terminals
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 absorber control switch is used to select the attenuation modes of the shock absorber. 2 levels of
attenuation, "SPORT" and "NORM", are available.

Fig. 67: Disconnecting Toe Control Link From Axle Carrier
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
12.SEPARATE SHOCK ABSORBER ASSY REAR LH
a. Remove the nut and disconnect the shock absorber arm from the axle carrier.

Fig. 68: Removing Shock Absorber Arm Nut
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
13.SEPARATE UPPER CONTROL ARM ASSY REAR LH
a. Loosen the nut to the top line of the bolt.
HINT:
Do not remove the nut.
b. Using SST, disconnect the upper control arm assy from the axle carrier.
SST 09628-0001 1

Fig. 73: Identifying Upper Control Arm Assy Rear LH Nut
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
20.INSTALL SHOCK ABSORBER ASSY REAR LH
a. Install the shock absorber assy LH with the new nut.
Torque: 70 N.m (714 kgf.cm, 52 ft.lbf)

Fig. 87: Disconnecting Upper Control Arm LH From Rear Axle Carrier
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
16.SEPARATE SHOCK ABSORBER ASSY REAR LH
a. Remove the nut and disconnect the shock absorber ass
y rear LH from the axle carrier.

Fig. 88: Removing Shock Absorber Assy Rear LH Nut
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
17.SEPARATE REAR SUSPENSION ARM ASSY NO. 1 LH
a. Remove the nut.
b. Using SST, disconnect the suspension arm assy No. 1 from the rear axle carrier.
SST 09628-0001 1