Combination LEXUS LS430 2003 Factory Service Manual

Fig. 25: Buzzer Problem Symptoms Table
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
HINT:
Refer to ON
-VEHICLE INSPECTION .
COMBINATION METER ASSY

Fig. 26: Identifying Terminals Of ECU (Combination Meter Assy)
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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

Fig. 28: Identifying Waveform 2
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Waveform 2 (Reference):
WAVEFORM 2 (REFERENCE)
HINT:
As vehicle speed increases, the cycle of the signal waveform narrows.
COMBINATION METER INNER CIRCUIT
ItemContents
Tool setting5V/DIV, 20 ms/DIV
Vehicle conditionDriving at approx. 20 Km/h (12 mph)

Fig. 29: Combination Meter Inner Circuit Diagram
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Fig. 30: Combination Meter Connector Terminals Reference Chart
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
1.CHECK DLC3
a. The vehicle's combination meter (ECU) uses CAN and the ISO 9141-2 for communication
protocol. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO
9141-2 format.

Fig. 43: Combination Meter Wiring Diagram
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INSPECT PROCEDURE
1.INSPECT COMBINATION METER ASSY
a. Measure the resistance according to the value (s) in the table below.
Standard
COMBINATION METER RESISTANCE SPECIFICATIONS
Terminal NoConditionSpecified condition

b. Measure the voltage according to the value (s) in the table below.
Standard
COMBINATION METER VOLTAGE SPECIFICATIONS
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
Fig. 44: Identifying Combination Meter Connector Terminals (Wire Harness View)

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: REPLACE COMBINATION METER ASSY (SEE OVERHAUL
)
C12-11 - Body groundAlwaysBelow 1 ohms
C12-22 - Body groundAlwaysBelow 1ohms
Terminal NoConditionSpecified condition
C12-12 - Body groundAlways10 to 14 V
C12-13 - Body groundAlways10 to 14 V
C12-1 - Body groundIgnition switch ACC or ON10 to 14 V

WIRING DIAGRAM
Fig. 45: Speedometer Wiring Diagram

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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:
SPEED 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 (VEHICLE SPEED SIGNAL)
a. Operate the han
d-held tester according to the steps on the display and select the "DATA LIST"
ItemTest DetailsDiagnostic
Note
SPEED
METER0 / 40(24) / 80(48) / 120(72) / 1 60(96) / 180(108) / 200(120) km/h
(mph)-

METER:
SPEED METER DATA LIST REFERENCE
OK:
Vehicle speed displayed on the tester is almost the same as the actual vehicle speed.
NG: Go to step 3
OK: REPLACE COMBINATION METER ASSY (SEE OVERHAUL
)
3.READ VALUE OF HAND-HELD TESTER (VEHICLE SPEED SIGNAL)
a. Operate the hand-held tester according to the steps on the display and select the "DATA LIST"
ABS:
ABS DATA LIST REFERENCE
OK:
Vehicle speed displayed on the tester is almost the same as the actual vehicle speed.
NG: GO TO BRAKE CONTROL SYSTEM (SEE HOW TO PROCEED WITH
TROUBLESHOOTING )
OK: GO TO NEXT STEP
4.INSPECT COMBINATION METER ASSY
INSPECTION USING OSCILLOSCOPE
a. Check the input signal waveform.
b. Remove the combination meter assy.
c. Connect the oscilloscope to the terminals C12-18 and body ground.
d. Start the en
gine.
ItemMeasurement Item/ Range (Display)Normal ConditionDiagnostic
Note
SPEED
METERVehicle speed / Min.: 0 km/h (0 mph),
Max.: 255 km/h (158 mph)Almost same as actual vehicle
speed (When driving)-
ItemMeasurement Item/ Range (Display)Normal ConditionDiagnostic
Note
(FR/FL/RR/RL)
SPDVehicle speed / Min.: 0 km/h (0 mph),
Max.: 326 km/h (202 mph)Almost same as actual speed
(When driving)-

Fig. 47: Identifying Signal Waveform
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
SIGNAL WAVEFORM CONDITIONS
OK:
As shown in the illustration
HINT:
As vehicle speed increases, the cycle of the signal waveform narrows.
NG: Go to step 5
OK: REPLACE COMBINATION METER ASSY (SEE OVERHAUL
)
ItemCondition
Tool setting5 V/DIV, 20 ms/DIV
Vehicle conditionDriving at approx. 20 Km/h (12 mph)