2003 LEXUS LS430 ignition

Fig. 14: Fail-Safe Chart
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
1.DATA LIST
a. Connect the hand-held tester to the DLC3.
b. Turn the ignition switch to the ON position.
c. Following the display on the han
d-held tester, read the "DATA LIST".

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. 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.

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.

NG: Go to step 3
OK: REPLACE SUSPENSION CONTROL ECU (SEE REPLACEMENT
)
3.CHECK HARNESS AND CONNECTOR (HEIGHT CONTROL SENSOR SUB-ASSY POWER
SOURCE) (SEE ELECTRONIC CIRCUIT INSPECTION PROCEDURE
)
a. Disconnect the height control sensor sub-assy connector.
b. Turn the ignition switch to the ON position.
c. Measure the voltage according to the value (s) in the table below.
TESTER CONNECTION STANDARD SPECIFIED CONDITION (FRONT RH)
Fig. 22: Identifying Front Height Control Sensor Sub
-Assy Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
TESTER CONNECTION STANDARD SPECIFIED CONDITION Standard (Front LH)
Tester ConnectionSpecified Condition
H14-1 (SHB) - H14-4 (SHG)4.5 to 5.5 V
Tester ConnectionSpecified Condition
H13-1 (SHB) - H13-4 (SHG)4.5 to 5.5 V

Fig. 48: Rear Acceleration Sensor Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
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 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.
DATA LIST AIR SUS
d. Check that the acceleration value of the acceleration sensor observed on the hand-held tester
changes when the vehicle is bounced.
Standard:
ItemNormal condition
G (UP & DOWN) FR (Right front acceleration sensor)0 +/- 31.9 mm/s2 at still condition
G (UP & DOWN) FL (Left front acceleration sensor)0 +/- 31.9 mm/s2 at still condition
G (UP & DOWN) R (Rear acceleration sensor)0 +/- 31.9 mm/s2 at still condition

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.
NORMAL CONDITION DESCRIPTION
d. Check the hardness of the absorber while operating the absorber control actuator level from 1 to 17
or from 17 to 1 through the ACTIVE TEST.
OK:
Hardness of the absorber becomes harder or softer.
NG: Go to step 2
OK: REPLACE SUSPENSION CONTROL ECU (SEE REPLACEMENT
)
2.INSPECT ABSORBER CONTROL ACTUATOR
a. Disconnect the absorber control actuator connector.
b. Measure the resistance according to the value (s) in the table below.
TESTER CONNECTION STANDARD SPECIFIED CONDITION STANDARD (FRONT RH)
ItemNormal Condition
DAMPER FR1 to 17 step (The absorber becomes softer as the level approaches to 1 and harder
as the level approaches to 17)
DAMPER FL1 to 17 step (The absorber becomes softer as the level approaches to 1 and harder
as the level approaches to 17)
DAMPER RR1 to 17 step (The absorber becomes softer as the level approaches to 1 and harder
as the level approaches to 17)
DAMPER RL1 to 17 step (The absorber becomes softer as the level approaches to 1 and harder
as the level approaches to 17)
Tester ConnectionSpecified Condition
1 (FBR+) - 3 (GND)12.0 to 12.8 ohms
2 (FAR+) - 3 (GND)12.0 to 12.8 ohms
3 (GND) - 4 (FBR-)12.0 to 12.8 ohms
3 (GND) - 5 (FAR-)12.0 to 12.8 ohms