2003 LEXUS LS430 Wiring engine

HINT:
*: For vehicles with a front seat climate control system
If the result is not as specified, the ECU may have a malfunction.
4.SEAT CLIMATE CONTROL BLOWER RH (RR) (CLIMATE CONTROL ECU)
Fig. 11: Identifying Terminals Of Climate Control ECU
- RH (RR)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
a. Disconnect the C29 and C30 blower connectors.
b. Measure the voltage and resistance of the wire harness side connector.
Standard:
TERMINAL DESCRIPTION AND SPECIFIED CONDITION
> Max. WARM
E (C28-8) - Body
groundB-R - Body
groundGround for seat heaterAlwaysBelow 1 V
IDL (C28-3) -
Body groundG - Body
groundEngine idle-up signal
Ignition switch: ON Turn
climate control switch: OFF --
> ON10 to 14 V --
> 0 V
Symbols
(Terminal No.)Wiring
ColorTerminal
DescriptionConditionSpecified Condition
GND (C29-11) -
Body groundW-B -
Body
ground
GroundAlwaysBelow 1 ohms
IG (C29-10) -
Body groundR-B - Body
groundPower sourceIgnition switch ON10 to 14 V
SW (C29-8) -
Body groundV-R -
Body Climate control
switchTurn climate control
switch ONBelow 1 ohms

Fig. 26: Identifying Terminals Of ECU (Combination Meter Assy)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
COMBINATION METER ASSY CONNECTOR TERMINALS REFERENCE
Symbols
(Terminals No.)Wiring
ColorTerminal DescriptionConditionSpecified
Condition
IG + (C12-1) -
Body groundY - Body
groundIgnition switch signal
(ON)Ignition switch OFF -->
ONBelow 1 V --> 10
to 14 V
MPX + (C12-2) -
Body groundGR-B -
Body groundMultiplex
communication signal--
MPX- (C12-3) -
Body groundGR-B -
Body groundMultiplex
communication signal--
S (C12-4) - Body
groundB-Y - Body
groundTachometer signalEngine runningPulse generation
(See waveform 1)
CHECK (C12-5) -
Body groundY-R - Body
groundCHECK ENGINE
signalCHECK ENGINE warning
light ON --> OFFBelow 1 V --> 10
to 14 V
TEMS (C12-6) -
Body groundY - Body
groundTEMS SPORT signalTEMS SPORT indicator
light ON --> OFFBelow 1 V --> 10
to 14 V
A/B (C12-7) - V-R (W) - ODO/TRIP signalIgnition switch ON,
ODO/TRIP switch ON -->
Below 1 V --> 4.5

METER ACTIVE TEST REFERENCE
WIRING DIAGRAM
and engine idling
TIRE PRESS WARNIndicat. Lamp TIRE PRESS (OFF/ON)Confirm that the vehicle is stopped
and engine idling
AUTO LV INDICIndicat. Lamp HEADLAMP AUTO
LEVELING (OFF/ON)Confirm that the vehicle is stopped
and engine idling
VSC INDICIndicat. Lamp VSC OFF (OFF/ON)Confirm that the vehicle is stopped
and engine idling
COMPASS DISPIndicat. COMPASS DISPLAY (OFF/ON)Confirm that the vehicle is stopped
and engine idling
ECONO INDICIndicat. Lamp ECONO (OFF/ON)Confirm that the vehicle is stopped
and engine idling
KEY REMND
BUZZRKey remained buzzer (OFF/ON)Confirm that the vehicle is stopped
and engine idling
LGT REMND
BUZZRLight remained buzzer (OFF/ON)Confirm that the vehicle is stopped
and engine idling
SEAT BELT BUZZRSeat Belt buzzer (OFF/ON)Confirm that the vehicle is stopped
and engine idling
REVERSE BUZZERReverse buzzer (OFF/ON)Confirm that the vehicle is stopped
and engine idling
S SHIFT RJCT BUZSports Shift reject buzzer (OFF/ON)Confirm that the vehicle is stopped
and engine idling
SPEED BUZZERSpeed buzzer (OFF/ON)Confirm that the vehicle is stopped
and engine idling
WARNING
BUZZERWarning buzzer (OFF/ON)Confirm that the vehicle is stopped
and engine idling
ItemTest DetailsDiagnostic Note
A/T SHIFT LCDA/T shift LCD (OFF/ON)Confirm that the vehicle is stopped and
engine idling
AFS INDICATORIndicat. Lamp AFS (OFF/ON)Confirm that the vehicle is stopped and
engine idling

WIRING DIAGRAM
Fig. 50: Tachometer Wiring Diagram

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.PERFORM ACTIVE TEST BY HAND-HELD TESTER
a. Operate the hand-held tester according to the steps on the display and select the "ACTIVE TEST".
METER:
TACHO METER ACTIVE TEST REFERENCE
OK:
Needle indication is normal.
NG: REPLACE COMBINATION METER ASSY (SEE OVERHAUL
)
OK: GO TO NEXT STEP
2.READ VALUE OF HAND-HELD TESTER (ENGINE SPEED SIGNAL)
a. Operate the han
d-held tester according to the steps on the display and select the "DATA LIST".
ItemTest DetailsDiagnostic
Note
TACHOMETEROrpm / 1000rpm / 2000rpm / 3000rpm / 4000rpm / 5000rpm /
6000rpm / 7000rpm-

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: GO TO ENGINE CONTROL SYSTEM (SEE REPLACEMENT
)
WIRING DIAGRAM
Fig. 55: Fuel Receiver Gauge Wiring Diagram

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.PERFORM ACTIVE TEST BY HAND-HELD TESTER
a. Operate the hand-held tester according to the steps on the display and select the "ACTIVE TEST".
METER:
METER ACTIVE TEST REFERENCE
OK:
Needle indication is normal.
NG: REPLACE COMBINATION METER ASSY (SEE OVERHAUL
)
ItemTest DetailsDiagnostic Note
FUEL GAUGEOFF, EMPTY, 1/2, FULL-

Fig. 63: Identifying Fuel Sender Gauge Assy And Luggage Room Junction Block Assy Connector
Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: REPLACE LUGGAGE ROOM JUNCTION BLOCK ASSY
WIRING DIAGRAM
Fig. 64: Water Temperature Receiver Gauge Wiring Diagram

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
HINT:
If there is an open or short in the engine coolant temperature sensor circuit, the ECM outputs DTCs. Perform
troubleshooting with the "SFI System 10-2".
1.PERFORM ACTIVE TEST BY HAND-HELD TESTER
a. Operate the hand-held tester according to the steps on the display and select the "ACTIVE TEST".
METER:
ACTIVE TEST REFERENCE

OK:
Needle indication is normal.
NG: REPLACE COMBINATION METER ASSY (SEE OVERHAUL
)
OK: GO TO NEXT STEP
2.READ VALUE OF HAND-HELD TESTER (ENGINE COOLANT)
a. Operate the hand-held tester according to the steps on the display and select the "DATA LIST".
ENGINE:
DATA LIST REFERENCE
OK:
Coolant temperature displayed on the tester is between 80°C (176°F) and 95°C (203°F) after
warning up.
NG: GO TO ENGINE CONTROL SYSTEM (SEE REPLACEMENT
)
OK: GO TO NEXT STEP
3.REPLACE COMBINATION METER ASSY
OK:
Normal operation
NG: GO TO ENGINE CONTROL SYSTEM (SEE REPLACEMENT
)
OK: END
WIRING DIAGRAM
ItemTest DetailsDiagnostic Note
COOLANT TEMPLOW /NORMAL /HI-
ItemMeasurement Item/ Range
(Display)Normal ConditionDiagnostic Note
COOLANT
TEMPCoolant Temperature / Min.: -
40°C (-40°F), Max.: 140°C
(284 °F)After warming up: 80
to 95°C (176 to 203°
F)If the value is "-40°C (-40°F)" or
"140°C (284°F)", sensor circuit is
open or shorted.

Fig. 65: Driver'S Seat Belt Warning Lamp Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
HINT:
If there is an open in the ground circuit (Airbag sensor assy center), the airbag sensor assy center outputs DTCs.
Perform troubleshooting with the "Supplemental Restraint System" 05-1026.
1.PERFORM ACTIVE TEST BY HAND-HELD TESTER
a. Operate the hand-held tester according to the steps on the display and select the "ACTIVE TEST".
METER:
ACTIVE TEST REFERENCE
OK:
Switch condition (ON/OFF) can be switched by ACTIVE TEST.
NG: REPLACE COMBINATION METER ASSY (SEE OVERHAUL
)
OK: GO TO NEXT STEP
ItemTest DetailsDiagnostic Note
D-BELT
REMINDIndicat. Lamp D-SEAT BELT
(OFF/ON)Confirm that the vehicle is stopped and engine
idling