2003 LEXUS LS430 Identifying condition

Fig. 84: Identifying Light Control Rheostat Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: GO TO NEXT STEP
4.REPLACE DRIVER SIDE JUNCTION BLOCK
OK:
Normal operation
NG: REPLACE COMBINATION METER ASSY (SEE OVERHAUL
)
OK: END
5.INSPECT LIGHT CONTROL RHEOSTAT
a. Disconnect the light control rheostat connector.
b. Measure the voltage according to the value (s) in the table below.
Standard
LIGHT CONTROL RHEOSTAT VOLTAGE SPECIFICATIONS
NG: REPLACE LIGHT CONTROL RHEOSTAT
Terminal NoConditionSpecified condition
1 - 2Rheostat knob turned fully clockwiseApprox. 0 kohms
1 - 2Rheostat knob turned fully counterclockwiseApprox. 10 +/- 2 kohms
1 - 3AlwaysApprox. 10 +/- 2 kohms
4 - 1,3Rheostat knob turned fully counterclockwise10 kohms or higher
4 - 1,3Rheostat knob turned to fully clockwiseBelow 1 ohms

Fig. 85: Identifying D6 And R4 Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
6.CHECK HARNESS AND CONNECTOR (LIGHT CONTROL RHEOSTAT - DRIVER SIDE
JUNCTION BLOCK) (SEE HOW TO PROCEED WITH TROUBLESHOOTING
)
a. Disconnect the D6 and R4 connectors.
b. Measure the resistance according to the value (s) in the table below.
Standard
D6 AND R4 CONNECTORS RESISTANCE SPECIFICATIONS
Tester ConnectionConditionSpecified Condition
D6-20 - R4-3AlwaysBelow 1 ohms
D6-22 - R4-2AlwaysBelow 1 ohms
D6-21 - R4-1AlwaysBelow 1 ohms
D6-1 - R4-4AlwaysBelow 1 ohms

c. Check the deflection width of the speedometer indicator.
Reference: Below 0.5 km/h (0.3 mph)
2.INSPECT OUTPUT OF VEHICLE SPEED
a. Check the output signal waveform.
1. Remove the combination meter assy.
2. Connect the oscilloscope to terminal C12-19 and body ground.
3. Start the engine.
Fig. 87: Identifying Terminal C12
-19
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
4. Check the signal waveform according to the condition (s) in the table below.
SIGNAL WAVEFORM CONDITIONS
ItemCondition
Tool setting5 V/DIV, 20 ms/DIV

OK:
As shown in the illustration
HINT:
As vehicle speed increases, the cycle of the signal waveform narrows.
Fig. 88: Identifying Signal Waveform

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
3.INSPECT TACHOMETER
a. Check operation
b. Connect the tune-up test tachometer and start the engine.
Vehicle conditionDriving at approx. 20 Km/h (12 mph)

Fig. 12: Identifying DLC3 Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
DLC3 CONNECTOR TERMINALS RESISTANCE SPECIFICATION
HINT:
If the displa
y shows "UNABLE TO CONNECT TO VEHICLE" when you have connected the
Symbols (Terminals No.)Terminal DescriptionConditionSpecified Condition
SIL(7) - SG(5)Bus "+" lineDuring transmissionPulse generation
CG(4) - Body groundChassis groundAlwaysBelow 1 ohms
SG(5) - Body groundSignal groundAlwaysBelow 1 ohms
BAT(16) - Body groundBattery positiveAlways11 to 14 V
CANH(6) - CANL(14)HIGH-level CAN bus lineIG switch OFF54 to 67 ohms
CANH(6) - Battery positiveHIGH-level CAN bus lineIG switch OFF1 Mohms or higher
CANH(6) - CG(4)HIGH-level CAN bus lineIG switch OFF3 kohms or higher
CANL(14) - Battery positiveLOW-level CAN bus lineIG switch OFF1 Mohms or higher
CANL(14) - CG(4)LOW-level CAN bus lineIG switch OFF3 kohms or higher

Fig. 21: Identifying Stop Lamp Switch Assy Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: Go to next step
3.CHECK HARNESS AND CONNECTOR (STOP LAMP SWITCH - BATTERY)
a. Measure the voltage according to the value(s) in the table below.
STOP LAMP SWITCH TERMINALS VOLTAGE SPECIFICATION
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
Tester connectionConditionSpecified condition
S19-2 - Body groundAlways10 to 14 V
S19-3 - Body groundIgnition SW ON10 to 14 V

Fig. 22: Identifying Stop Lamp Switch Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: Go to next step
4.INSPECT ECM
a. Reconnect the stop lamp switch connector.
b. Disconnect the E2 and E3 connectors from the ECM.
c. Turn the ignition switch to the ON position.
d. Measure the voltage according to the value(s) in the table below.
ECM CONNECTOR TERMINALS VOLTAGE RESISTANCE SPECIFICATION
RESULT DETAIL
Pedal conditionTester connectionSpecification
DepressedE2-4 (STP) - Body ground10 to 14 V
ReleasedE2-4 (STP) - Body groundBelow 1 V
DepressedE3-8 (ST1-) - Body groundBelow 1 V
ReleasedE3-8 (ST1-) - Body ground10 to 14 V

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
A: REPLACE ECM (SEE REPLACEMENT
)
5.INSPECT DRIVER SIDE J/B
a. Measure the voltage according to the value(s) in the table below.
Fig. 24: Identifying Driver Side Junction Block ECU Connectors

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DRIVER SIDE JUNCTION BLOCK ECU TERMINALS VOLTAGE SPECIFICATION
NG: Go to step 6
OK: REPAIR OR REPLACE HARNESS OR CONNECTOR (DRIVER SIDE J/B ECU - ECM)
6.INSPECT DRIVER SIDE J/B
Pedal conditionTester connectionSpecification
DepressedD3-12 (STPO) - Body ground10 to 14 V
ReleasedD3-12 (STPO) - Body groundBelow 1 V