LEXUS LS430 2003 Factory Repair Manual

Fig. 48: Identifying C12 And S42 Connectors
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR
OK: GO TO NEXT STEP
6.INSPECT ABS & TRACTION ACTUATOR ASSY (VSC)
a. Disconnect the S42 connector.
b. Measure the voltage according to the value (s) in the table below.
Standard
S42 connector VOLTAGE SPECIFICATIONS
NG: REPLACE COMBINATION METER ASSY (SEE OVERHAUL
)
Fig. 49: Identifying S42 Connector Terminals

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: GO TO BRAKE CONTROL SYSTEM (SEE HOW TO PROCEED WITH
TROUBLESHOOTING )
Tester ConnectionConditionSpecified Condition
S42-12 - Body groundIgnition switch ON10 to 14 V

WIRING DIAGRAM
Fig. 50: Tachometer 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:
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-

METER:
TACHO METER DATA LIST REFERENCE
OK:
Engine speed displayed on the tester is almost the same as the actual engine speed.
NG: Go to step 3
OK: REPLACE COMBINATION METER ASSY (SEE OVERHAUL
)
3.READ VALUE OF HAND-HELD TESTER (ENGINE SPEED SIGNAL)
a. Operate the hand-held tester according to the steps on the display and select the "DATA LIST".
ENGINE:
DATA LIST REFERENCE
OK:
Engine speed displayed on the tester is almost the same as the actual engine speed.
NG: GO TO ENGINE CONTROL SYSTEM (SEE REPLACEMENT
)
OK: GO TO NEXT STEP
4.INSPECT COMBINATION METER ASSY
INSPECTION USING OSCILLOSCOPE
a. Check the input signal waveform.
1. Remove the combination meter assy.
2. Connect the oscilloscope to the terminals C12-4 and body ground.
3. Start the engine.
4. Check the si
gnal waveform according to the condition (s) in the table below.
ItemMeasurement Item/ Range
(Display)Normal ConditionDiagnostic
Note
TACHO
METEREngine speed / Min.: 50 rpm,
Max.: 12,750 rpmAlmost same as actual engine speed
(When engine is running)-
ItemMeasurement Item/ Range
(Display)Normal ConditionDiagnostic
Note
ENGINE
SPDEngine speed / Min.: 50 rpm,
Max.: 12,750 rpmAlmost same as actual engine speed
(When engine is running)-

SIGNAL WAVEFORM CONDITION
OK:
As shown in the illustration
Fig. 51: Identifying Terminals C12
-4
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ItemCondition
Tool setting5 V/DIV, 10 ms/DIV
Vehicle conditionEngine idle speed

Fig. 52: Identifying Signal Waveform
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: Go to step 5
OK: REPLACE COMBINATION METER ASSY (SEE OVERHAUL
)
5.CHECK HARNESS AND CONNECTOR (ECM - COMBINATION METER ASSY) (SEE HOW
TO PROCEED WITH TROUBLESHOOTING )
a. Disconnect the C12 and E2 connectors.
b. Measure the resistance according to the value (s) in the table below.
Standard
C12 AND E2 CONNECTORS RESISTANCE SPECIFICATIONS
Tester ConnectionConditionSpecified Condition
C12-4 - E2-16AlwaysBelow 1 ohms
C12-4 - Body groundAlways10 kohms or higher

Fig. 53: Identifying C12 And E2 Connectors
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR
OK: GO TO NEXT STEP
6.INSPECT COMBINATION METER ASSY
a. Disconnect the E2 connector.
b. Measure the voltage according to the value (s) in the table below.
Standard
E2 CONNECTOR VOLTAGE SPECIFICATIONS
NG: REPLACE COMBINATION METER ASSY (SEE OVERHAUL
)
Fig. 54: Identifying E2 Connector

Tester ConnectionConditionSpecified Condition
E2-16 - Body groundIgnition switch ON10 to 14 V

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-

OK: GO TO NEXT STEP
2.READ VALUE OF HAND-HELD TESTER (FUEL GAUGE)
a. Operate the hand-held tester according to the steps on the display and select the "DATA LIST".
METER:
Fig. 56: Data List Reference Table (Meter)

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OK:
Fuel value signal displayed on the tester is almost the same as needle indication.
NG: REPLACE COMBINATION METER ASSY (SEE OVERHAUL
)
OK: GO TO NEXT STEP
3.READ VALUE OF HAND-HELD TESTER (FUEL GAUGE)
a. Operate the hand-held tester according to the steps on the display and select the "DATA LIST".
BODY No.4:
Fig. 57: Data List Reference Table (Body No.4)

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OK:
Fuel value signal displayed on the tester is almost the same as needle indication.
NG: Go to step 4
OK: Go to step 4
REPLACE LUGGAGE ROOM JUNCTION BLOCK ASSY
OK:
Normal operation
NG: REPLACE COMBINATION METER ASSY (SEE OVERHAUL
)
OK: END
4.INSPECT FUEL SENDER GAUGE ASSY (MAIN)
a. Measure the voltage according to the value (s) in the table below.
Standard
FUEL SENDER GAUGE CONNECTOR TERMINALS VOLTAGE SPECIFICATIONS
b. Remove the fuel sender gauge assy.
c. Connect the fuel sender gauge connector.
d. Check that the float position is between E and F.
e. Measure the voltage between the terminals 2 and 1 of connector according to the value (s) in the
table below.
Standard
VOLTAGE SPECIFICATIONS
NG: REPLACE FUEL SENDER GAUGE ASSY (MAIN)
Tester ConnectionConditionSpecified Condition
F19-1 - F19-3Ignition switch ACC or ONBelow 1 to 5 V
Float levelFloat position mm (in.)Voltage (V)
F-34.8 (-1.37) +/- 3(0.12)4.5 to 4.75
1/292.8(3.65) +/- 3(0.12)1.41 +/- 1.61
Warning137.0(5.39) +/- 3(0.12)0.20 to 0.45