2003 LEXUS LS430 sensor

1.DIAGNOSIS SYSTEM
a. Inspect the battery voltage.
Battery voltage: 11 to 14 V
If the voltage is below 11 V, recharge the battery before proceeding.
b. Check DLC3.
The suspension control ECU uses the CAN system and ISO 9141-2 for communication. The
terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 9141-2 format.
Verify the conditions listed in the table below:
SGL2 (A22-23) -
GND (A20-4)GR - W-BHeight control sensor
ground (RL)AlwaysBelow 1
ohms
SBL2 (A22-24) -
GND (A20-4)BR - W-BHeight control sensor
power source (RL)IG switch ON4.5 to 5.5 V
SGR2 (A22-25) -
GND (A20-4)V - W-BHeight control sensor
ground (RR)AlwaysBelow 1
ohms
SBR2 (A22-26) -
GND (A20-4)B - W-BHeight control sensor
power source (RR)IG switch ON4.5 to 5.5 V
SGRR (A22-27) -
GND (A20-4)L - W-BAcceleration sensor
(rear)IG switch ON, keep the vehicle still
without any vertical movement for
1 secondApprox. 2.5
V
SHRR (A22-28) -
GND (A20-4)P - W-BHeight control sensor
(RR)IG switch ON0.5 to 4.5 V
SHRR (A22-28) -
GND (A20-4)P - W-BHeight control sensor
(RR)Engine idling, height control switch
"NORM"Approx. 2.5
V
SGFL (A22-29) -
GND (A20-4)B - W-BAcceleration sensor
(front)IG switch ON, keep the vehicle still
without any vertical movement for
1 secondApprox. 2.5
V
SHRL (A22-30) -
GND (A20-4)LG - W-BHeight control sensor
(RL)IG switch ON0.5 to 4.5 V
SHRL (A22-30) -
GND (A20-4)LG - W-BHeight control sensor
(RL)Engine idling, height control switch
"NORM"Approx. 2.5
V

Fig. 11: Identifying Absorber Control Indicator Lamp Location (1 Of 2)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
d. DTCs (Normal mode)
1. DTCs are memorized in the suspension control ECU and read by using the hand-held tester
(SEE DTC CHECK/CLEAR
for the procedure of DTCs check).
e. Test mode
1. By switching from normal mode into test mode, you can inspect the height control switch,
absorber control switch, front acceleration sensor and rear acceleration sensor (SEE TEST
MODE PROCEDURE ).
2.CHECK INDICATOR LAMP
1. Turn the ignition switch to the ON position.
2. Check that the absorber control indicator lamp comes on for 2 seconds.
If the indicator check result is not normal, proceed to troubleshooting for the indicator lamp circuit.
TROUBLE AREA REFERENCE
Trouble AreaSee Procedure
Absorber control indicator lamp ABSORBER CONTROL INDICATOR LAMP

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

For details of each code, go to Fig. 16
DTC C1715, DTC C1716, DTC C1717,
DTC C1791, DTC C1792, DTC C1793
RIGHT FRONT ACCELERATION SENSOR CIRCUIT
DTC C1725, DTC C1726, DTC C1727,
DTC C1728
RIGHT FRONT ABSORBER CONTROL ACTUATOR
CIRCUIT
DTC C1735EXHAUST SOLENOID VALVE CIRCUIT
DTC C1737, DTC C1738, DTC C1739,
DTC C1740
RIGHT FRONT HEIGHT CONTROL SOLENOID
VALVE CIRCUIT
DTC C1741AIR SUS RELAY CIRCUIT
DTC C1742HEIGHT CONTROL COMPRESSOR CIRCUIT
DTC C1751, DTC C1752CONTINUOUS ELECTRIC CURRENT TO HEIGHT
CONTROL COMPRESSOR
DTC C1761ECU MALFUNCTION
DTC C1774POWER SOURCE CIRCUIT
DTC C1776SPEED SENSOR CIRCUIT
DTC C1777STEERING ANGLE SENSOR CIRCUIT
DTC C1786HEIGHT CONTROL SWITCH CIRCUIT (TEST
DIAGNOSIS)
DTC C1787ABSORBER CONTROL SWITCH CIRCUIT (TEST
DIAGNOSIS)

Fig. 17: Diagnostic Trouble Code Information Chart (2 Of 2)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
*1: For codes in the "Indicator Light" column with a "circ" mark, the absorber control indicator lamp blinks at 1
second intervals.
*2: For codes in the "Indicator Light" column with a " (xcirc)" mark, when trouble occurs, "HEIGHT HI" is
displayed on the multi-information display. Also, the master warning light is lit on the combination meter and
an alarm sounds.
*3: Since the relief pressure of the compressed air is 980 kPa (10 kgf/cm
2 , 142 psi), if vehicle height control is
attempted on a steeply sloping road, when the vehicle is overloaded, or when the vehicle height is jacked up
with the engine running, code "C1751" may be output and vehicle height control may be suspended. (This is not
abnormal.) In this case, however, when detecting the first error, approximately 10 minutes after the ignition
switch was turned to the ON position, vehicle height control is resumed. When the following errors are
detected, it takes 70 minutes until the control is resumed.
*4: If vehicle height control is operated while the wheels are removed or the vehicle is jacked up, code "C1752"
may be output, but this is not abnormal. When code "C1752" is output, vehicle height control is not carried out.
However, control is resumed if the ignition switch is turned off, then to the ON position again.
CIRCUIT DESCRIPTION
The height control sensor sub-assy controls the resistance value by following changes in vehicle height. The
suspension control ECU detects the change in vehicle height from the transformed voltage. The suspension
control ECU outputs a constant voltage of 5 V to the SHB terminal of the height control sensor sub-assy.
In the height control sensor, the voltage is changed due to resistance. The changed voltage is output from the

SHFR terminal of the height control sensor sub-assy to suspension control ECU, thus the vehicle height is
detected.
Fig. 18: Front Height Control Sensor Circuit Description

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
HINT:
If DTC C1711, C1712, C1713 or C1714 is output, vehicle height control is suspended.
If the normal signal is output from the height control sensor sub-assy while suspending vehicle height
<004600520051005700550052004f000f000300590048004b004c0046004f00480003004b0048004c004a004b00570003004600520051005700550052004f0003004c005600030055004800560058005000480047001100030037004b004800030052005300
48005500440057004c005200510003004c005600030044004f[so resumed when the ignition switch is
turned off once, then turned on again.

Fig. 20: Front Height Control Sensor Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
HINT:

Proceed to troubleshooting following the flow chart, regardless of whether or not DTC C1711, C1712, C1713
or C1714 is displayed.
1.RECONFIRM DTC
a. Check DTCs (SEE DTC CHECK/CLEAR
).
1. Confirm if DTC C1761 and/or C1774 is recorded.
OK:
DTC C1761 and/or C1774 is not output.
HINT:
If either DTC C1761 (ECU malfunction) (SEE DTC C1761 ECU MALFUNCTION
or DTC C1774
POWER SOURCE CIRCUIT ) is displayed, carry out the necessary inspection. If they are output at the
same time, carry out the necessary inspection for DTC C1774 first.
NG: REPAIR CIRCUIT INDICATED BY OUTPUT CODE
OK:Go to next step
2.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 turn the hand-held tester main switch on.
c. Select the item below in the DATA LIST and read its value displayed on the hand-held tester.
AIRSUS:
Fig. 21: Air sus
- Data List
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
d. Check the vehicle height value of each sensor while pressing the height control switch "UP" and
"DOWN".
OK:
Vehicle height value changes.