Combination LEXUS LS430 2003 Factory User Guide

Fig. 126: Inspecting Pad Wear Indicator Wire Assy
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Standard:
TESTER CONNECTION SPECIFIED CONDITION
REAR:
HINT:
Check that there are no scratches or cracks on the pad wear indicator.
a. Remove the rear wheel RH.
b. Disconnect the pad wear indicator connector.
c. Measure the resistance according to the value (s) in the table below.
Standard:
TESTER CONNECTION SPECIFIED CONDITION
NG: REPLACE PAD WEAR INDICATOR WIRE ASSY
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
The skid control ECU detects the TRAC control main switch ON/OFF signal and turns the TRAC OFF light
on/off.
When the TRAC control switch is pressed, the TRAC control does not operate and the TRAC OFF light comes
on.
The skid control ECU connected to the combination meter via CAN and MPX communications.
Tester ConnectionSpecified Condition
Terminal a - Terminal bBelow 1 ohms
Terminal a - Body ground1 Mohms or higher
Tester ConnectionSpecified Condition
Terminal a - Terminal bBelow 1 ohms
Terminal a - Body ground1 Mohms or higher

1.PERFORM ACTIVE TEST BY HAND-HELD TESTER (TRAC OFF INDICATOR LIGHT)
a. Connect the hand-held tester to the DLC3.
b. Start the engine.
c. Select the item "TRAC OFF LIGHT" in the ACTIVE TEST and operate the TRAC OFF indicator
light on the hand-held tester.
VEHICLE CONDITION / TEST DETAILS
d. Check that "ON" and "OFF" of the TRAC OFF indicator light are indicated on the combination
meter when using the hand-held tester.
OK: Go to next step
Turn the TRAC OFF indicator light on or off in accordance with the hand-held tester.
NG: Go to step 5
OK: Go to next step
2.INSPECT MULTIPLEX COMMUNICATION SYSTEM
a. Is the DTC output for Multiplex communication system?
Result:
DTC OUTPUT DESCRIPTION
B: REPAIR MULTIPLEX COMMUNICATION SYSTEM (SEE DIAGNOSTIC TROUBLE
CODE CHART )
A: Go to next step
3.INSPECT CAN COMMUNICATION SYSTEM
a. Is the DTC output for CAN communication system?
Result:
DTC OUTPUT DESCRIPTION
ItemVehicle Condition / Test DetailsDiagnostic Note
VSC / TRAC OFF INDTurns VSC / TRAC OFF indicator ON / OFFObserve combination meter
DTC is not outputA
DTC is outputB
DTC is not outputA
DTC is outputB

Fig. 129: Identifying Skid Control ECU Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: Go to next step
6.INSPECT COMBINATION METER ASSEMBLY (SEE PROBLEM SYMPTOMS TABLE
)
NG: REPAIR OR REPLACE COMBINATION METER ASSEMBLY
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
The SLIP indicator blinks during TRAC & VSC operation.
The skid control ECU is connected to the combination meter via CAN and MPX communications.
WIRING DIAGRAM

a. Connect the hand-held tester to the DLC3.
b. Start the engine.
c. Select the item "SLIP INDI LIGHT" in the ACTIVE TEST and operate the SLIP indicator light on
the hand-held tester.
VEHICLE CONDITION / TEST DETAILS
d. Check that "ON" and "OFF" of the SLIP indicator light are indicated on the combination meter
when using the hand-held tester.
OK: Go to next step
Turn the SLIP indicator light on or off in accordance with the hand-held tester.
NG: Go to step 2
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
2.INSPECT MULTIPLEX COMMUNICATION SYSTEM
a. Is the DTC output for Multiplex communication system?
Result:
DTC OUTPUT DESCRIPTION
B: REPAIR MULTIPLEX COMMUNICATION SYSTEM (SEE DIAGNOSTIC TROUBLE
CODE CHART )
A: Go to next step
3.INSPECT CAN COMMUNICATION SYSTEM
a. Is the DTC output for CAN communication system?
Result:
DTC OUTPUT DESCRIPTION
ItemVehicle Condition / Test DetailsDiagnostic Note
SLIP INDI LIGHTTurns SLIP indicator light ON / OFFObserve combination meter
DTC is not outputA
DTC is outputB
DTC is not outputA

B: REPAIR CAN COMMUNICATION SYSTEM (SEE PRECAUTION )
A: Go to next step
4.INSPECT COMBINATION METER ASSEMBLY (SLIP INDICATOR LIGHT) (SEE PROBLEM
SYMPTOMS TABLE )
NG: REPAIR OR REPLACE COMBINATION METER ASSEMBLY
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
The skid control buzzer sounds and VSC warning (Multi-information display) comes ON during VSC
operation.
WIRING DIAGRAM
DTC is outputB

Fig. 6: Air Conditioning System Diagram (2 Of 2)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
1.GENERAL
a. The air conditioning system has the following features:
In compliance with the temperature set at the temperature control switch, the neural network
control calculates the outlet temperature based on the input signals from various sensors. In
addition, corrections in accordance with the signals from the evaporative temperature sensor
and the water temperature sensor are added to control the outlet air temperature.
Controls the front and rear blower motors in accordance with the airflow volume that has
been calculated by the neural network control based on the input signals from various
sensors.
Automatically switches the outlets in accordance with the outlet mode ratio that has been
calculated by the neural network control based on the input signals from various sensors.
Automatically controls the air inlet control damper in accordance with the airflow volume
that has been calculated by the neural network control.
Turns the compressor on/off and controls the discharge capacity based on the signals from
various sensors.
Based on the signals from the ambient temperature sensor, this control calculates the outside
temperature, which is then corrected in the air conditioner ECU, and shown in the multi-
information display in the combination meter.
Switched the rear defogger and outside rear view mirror heaters on for 15 minutes when the
rear defogger switch is switched on. Switched them off if the switch is pressed while they are
operating.
Controls the orientation and the angle of the front center register based on the input signals
from various sensors and on the outlet mode.
Determines whether the clean air filter (for the front A/C) is clogged by monitoring the air
inlets, and airflow volume.
The A/C amplifier automatically controls the air inlets based on the signals from the smog
ventilation sensor.
Improves the air quality by linking the air inlet control damper and the blower motor (for the
rear A/C and air purifier), based on the signals from the exhaust gas sensor and the smoke
sensor.
Checks the sensors in accordance with operation of the air conditioner switches.
2.MODEL POSITION AND DAMPER OPERATION

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

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

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
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. 142: Identifying Combination Meter Assy Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK:Go to next step
2.CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSY - BODY GROUND)
(SEE ELECTRONIC CIRCUIT INSPECTION PROCEDURE
)
a. Measure the resistance according to the value (s) in the table below.
TESTER CONNECTION STANDARD SPECIFIED CONDITION
Tester ConnectionSpecified Condition
C12-11 - Body groundBelow 1 ohms

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