2003 LEXUS LS430 Rear suspension

Fig. 7: ABS & TRACTION Actuator - Traction Control
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Operation description
The skid control ECU detects vehicle's slip condition by receiving signals from the speed sensor
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380003004600520051005700550052004f0056000300480051[gine torque with the ECM,
vehicle position with suspension control ECU via CAN communication, and oil pressure with the
pump and solenoid valve. The SLIP indicator lamp blinks when the system is operating. TRAC
OFF switch stops traction control operation.
e. VSC (Vehicle Stability Control)
The VSC system helps prevent the vehicle from slipping sideways as a result of strong front wheel skid or
stron
g rear wheel skid during cornering.

HINT:
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.
When entering the test mode, the suspension control ECU sets all the test mode DTCs first.
After completing the test mode for each check item, the test mode DTCs that are determined
normal by the suspension control ECU will be erased.
The test mode DTCs for other check items may not be erased when only a certain signal is
inspected.
When the test mode returns back to the normal mode, all the test mode DTCs will be erased.
a. Procedure for Test Mode.
1. Make sure that the ignition switch is off.
2. Set each of the check items to the condition in Operation (A) in the Test mode table below.
3. Connect the hand-held tester to the DLC3.
4. Turn the ignition switch to the ON position.
5. Select the SIGNAL CHECK mode on the hand-held tester.
6. Set each of the check items to the condition in Operation (B) in the Test mode table below.

FBL+ (A21-6) -
FBL- (A21-16)G-W - G-
OSuspension control
actuator (FL)IG switch ONBelow 1
ohms
SLRL (A21-7) -
GND (A20-4)P-L - W-BHeight control solenoid
valve (RL)IG switch ONBelow 1 V
SLRL (A21-7) -
GND (A20-4)P-L - W-BHeight control solenoid
valve (RL)Engine idling, height control switch
from "NORM" to "HIGH" or
reverse
8 V or more
SLRR (A21-8) -
GND (A20-4)P - W-BHeight control solenoid
valve (RR)IG switch ONBelow 1 V
SLRR (A21-8) -
GND (A20-4)P - W-BHeight control solenoid
valve (RR)Engine idling, height control switch
from "NORM" to "HIGH" or
reverse
8 V or more
RM+ (A21-17) -
GND (A20-4)BR-Y - W-
BMotor lock (+)
Engine idling, height control switch
from "NORM" to "HIGH" during
compressor operation
Below 1 V
RM- (A21-18) -
GND (A20-4)BR-B - W-
BMotor lock (-)AlwaysBelow 1
ohms
SHR2 (A21-19) -
GND (A20-4)W - W-BHeight control sensor
(HID rear)IG switch ON0.5 to 4.5 V
SHFR (A21-20) -
GND (A20-4)B-W - W-
BHeight control sensor
(FR)IG switch ON0.5 to 4.5 V
SHFR (A21-20) -
GND (A20-4)B-W - W-
BHeight control sensor
(FR)Engine idling, height control switch
"NORM"Approx. 2.5
V
SHF2 (A21-21) -
GND (A20-4)V-G - W-BHeight control sensor
(HID front)IG switch ON0.5 to 4.5 V
SHFL (A21-22) -
GND (A20-4)L - W-BHeight control sensor
(FL)IG switch ON0.5 to 4.5 V
SHFL (A21-22) -
GND (A20-4)L - W-BHeight control sensor
(FL)Engine idling, height control switch
"NORM"Approx. 2.5
V
SBL3 (A21-23) -
GND (A20-4)B - W-BHeight control sensor
power source (HID)IG switch ON4.5 to 5.5 V
SGL3 (A21-24) -
GND (A20-4)V-Y - W-BHeight control sensor
ground (HID)AlwaysBelow 1
ohms
RAR+ (A22-2) -
RAR- (A22-3)Y - SBSuspension control
actuator (RR)IG switch ONBelow 1
ohms
RBR+ (A22-4) -
RBR- (A22-5)LG - PSuspension control
actuator (RR)IG switch ONBelow 1
ohms
RAL+ (A22-6) -
RAL- (A22-7)L - GSuspension control
actuator (RL)IG switch ONBelow 1
ohms
RBL+ (A22-8) -
RBL- (A22-9)O - BRSuspension control
actuator (RLIG switch ONBelow 1
ohms
SGR3 (A22-12) -
GND (A20-4)W - W-BAcceleration sensor
ground (rear)AlwaysBelow 1
ohms
SBR3 (A22-15) -
GND (A20-4)R - W-BAcceleration sensor
power source (rear)IG switch ON4.5 to 5.5 V

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

Fig. 33: Identifying Height Control Sensor Rear LH Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
B: REPLACE HEIGHT CONTROL SENSOR SUB-ASSY FRONT RH (SEE REPLACEMENT
)
C: REPLACE HEIGHT CONTROL SENSOR SUB-ASSY FRONT LH (SEE REPLACEMENT
)
D: REPLACE HEIGHT CONTROL SENSOR SUB-ASSY REAR RH (SEE REPLACEMENT
)
E: REPLACE HEIGHT CONTROL SENSOR SUB-ASSY REAR LH (SEE REPLACEMENT
)
A: REPLACE SUSPENSION CONTROL ECU (SEE REPLACEMENT
)
4.CHECK HARNESS AND CONNECTOR (SUSPENSION CONTROL ECU - HEIGHT
CONTROL SENSOR SUB-ASSY) (SEE ELECTRONIC CIRCUIT INSPECTION PROCEDURE
)
a. Disconnect the suspension control ECU A20 or A22 connector.
b. Measure the resistance according to the value (s) in the table below.

Fig. 37: Identifying Height Control Sensor Sub-Assy Rear LH Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK:Go to next step
5.CHECK HARNESS AND CONNECTOR (SUSPENSION CONTROL ECU - HEIGHT
CONTROL SENSOR SUB-ASSY) (SEE ELECTRONIC CIRCUIT INSPECTION PROCEDURE
)
a. Disconnect the suspension control ECU A21 or A22 connector.
b. Measure the resistance according to the value (s) in the table below.