2003 LEXUS LS430 Diagram AC

Fig. 121: DTC C1776 Detecting Condition And Trouble Area
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
WIRING DIAGRAM
Fig. 122: Speed Sensor Wiring Diagram

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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.
NORMAL CONDITION AIRSUS
d. Check that there is no difference between the speed value output from the speed sensor displayed
on the hand-held tester and the speed value displayed on the speedometer when driving the vehicle.
OK:
There is almost no difference in the displayed speed values.
ItemNormal Condition
WHEEL SPD FRActual vehicle speed

HINT:
There is tolerance of +/- 10 % in the speedometer indication.
NG: Go to step 2
OK: REPLACE SUSPENSION CONTROL ECU (SEE REPLACEMENT
)
2.CHECK DIAGNOSTIC CODE OUTPUT
a. Check if the normal system code is output in the VSC system (SEE DTC CHECK/CLEAR
).
OK:
No DTC is output in the VSC system.
NG: REPAIR CIRCUIT INDICATED BY OUTPUT CODE
OK:Go to next step
3.CHECK DIAGNOSTIC CODE OUTPUT
a. Check if the normal system code is output in the CAN communication system (SEE HOW TO
PROCEED WITH TROUBLESHOOTING ).
OK:
No DTC is output in the CAN communication system.
NG: REPAIR CIRCUIT INDICATED BY OUTPUT CODE
OK: REPLACE SUSPENSION CONTROL ECU (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
The steering angle sensor signal is sent to the suspension control ECU through the CAN communication
system. When there is a communication malfunction, it will be detected by the diagnosis function.
Fig. 123: DTC C1777 Detecting Condition And Trouble Area

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

Fig. 124: Steering Angle Sensor Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.READ VALUE ON HAND-HELD TESTER
a. Connect the han
d-held tester to the DLC3.

Fig. 127: DTC C1786 Detecting Condition And Trouble Area
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
HINT:
DTC C1786 is output only in the test mode.
WIRING DIAGRAM
Fig. 128: Height Control Switch 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.
AIRSUS:

Fig. 134: DTC C1787 Detecting Condition And Trouble Area
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
HINT:
DTC C1787 is output only in the test mode.
WIRING DIAGRAM
Fig. 135: Absorber Control Switch Wiring Diagram

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INSPECTION PROCEDURE
1.INSPECT ABSORBER CONTROL SWITCH
a. Disconnect the absorber control switch connector.
b. Measure the resistance according to the value (s) in the table below.
TESTER CONNECTION STANDARD SPECIFIED CONDITION
Switch ConditionTester ConnectionSpecified Condition
"SPORT"2 (GND) - 4 (ECU1)Below 1 ohms
"NORM"2 (GND) - 4 (ECU1)10 Kohms or higher

WIRING DIAGRAM
Fig. 140: Height Control Indicator Lamp Wiring Diagram

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INSPECTION PROCEDURE
1.CHECK HARNESS AND CONNECTOR (SUSPENSION CONTROL ECU - COMBINATION
METER ASSY) (SEE ELECTRONIC CIRCUIT INSPECTION PROCEDURE
)
a. Disconnect the suspension control ECU A20 connector.
b. Disconnect the combination meter assy C12 connector.
c. Measure the resistance according to the value (s) in the table below.
TESTER CONNECTION STANDARD SPECIFIED CONDITION
Tester ConnectionSpecified Condition
A20-19 (VH) - C12-17Below 1 ohms
A20-19 (VH) - Body ground10 Kohms or higher

Fig. 143: Identifying Combination Meter Assy Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN ON PROBLEM SYMPTOMS
TABLE
CIRCUIT DESCRIPTION
The absorber control indicator is displayed when pressing the "SPORT" button of the absorber control switch. I
f
the suspension control ECU detects trouble, it lights the absorber control indicator and at the same time
prohibits suspension control. At this time, the ECU records the DTC in memory.
WIRING DIAGRAM

Fig. 147: Identifying Combination Meter Assy Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN ON PROBLEM SYMPTOMS
TABLE
CIRCUIT DESCRIPTION
By connecting terminals OPB and CG of the DLC3, vehicle height control is not carried out.
WIRING DIAGRAM