2003 LEXUS LS430 Identifying condition

Fig. 87: Disconnecting ECM Connector
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NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: Go To Next Step.
5.CHECK HARNESS AND CONNECTOR (SPIRAL CABLE SUB-ASSY - BODY GROUND)
a. Measure the resistance according to the value(s) in the table below.
Standard:
SPIRAL CABLE SUB-ASSY CONNECTOR TERMINALS RESISTANCE
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
Fig. 88: Identifying Spiral Cable Sub
-Assy Connector Terminals
Tester connectionConditionSpecified value
C13-3 - Body groundAlwaysBelow 1 ohms

Fig. 89: Wiring Diagram - Diagnosis Circuit
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HINT:
When a particular warning light stays blinking, a ground short in the wiring of terminal TC of the DLC3 or an
internal ground short in the relevant ECU is suspected.
INSPECTION PROCEDURE
1.CHECK HARNESS AND CONNECTOR (TC of DLC3 - ECM)
a. Disconnect the E2 connector from the ECM.
b. Measure the resistance according to the value(s) in the table below.
Standard:
ECM CONNECTOR TERMINALS RESISTANCE
Fig. 90: Identifying DLC3 Connector (TC) Terminals

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Tester connectionConditionSpecified condition
TC (E2-3) - TC (D1 - 13)AlwaysBelow 1 ohms

Fig. 91: Disconnecting E2 Connector From ECM
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (DLC3 - ECM)
OK: Go To Next Step.
2.CHECK HARNESS AND CONNECTOR (CG of DLC3 - BODY GROUND)
a. Measure the resistance according to the value(s) in the table below.
Standard:
ECM CONNECTOR TERMINALS RESISTANCE
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (DLC3 - BODY GROUND)
Fig. 92: Identifying DLC3 Connector (CG) Terminals

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Tester connectionConditionSpecified condition
CG (D1-4) - Body groundAlwaysBelow 1 ohms

OK: Go To Next Step.
3.CHECK HARNESS AND CONNECTOR (TC of DLC3 - BODY GROUND)
a. Measure the resistance according to the value(s) in the table below.
Standard:
ECM CONNECTOR TERMINALS RESISTANCE
NG: REPAIR OR REPLACE WIRE HARNESS AND EACH ECU
Fig. 93: Identifying DLC3 Connector (TC) Terminals

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OK: REPLACE ECM (SEE REPLACEMENT
)
Tester connectionConditionSpecified condition
TC (D1-13) - Body groundAlways10 kohms or higher

Fig. 19: Identifying Vehicle Speed Pattern
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HINT:
*1: Drive at such a speed in the uppermost gear, to engage lock-up. The vehicle can be driven at a speed
lower than that in the above diagram under the lock-up condition.
PROBLEM SYMPTOMS TABLE
HINT:
If a normal code is displayed during the diagnostic trouble code check although the trouble still occurs, check
the electrical circuits for each symptom in the order given in the following charts.
The Matrix Chart is divided into 2 chapters.
1.Chapter 1: Electronic Circuit Matrix Chart
Refer to the table below when the trouble cause is considered to be electrical.
If the instruction "Proceed to next circuit inspection shown on matrix chart" is given in the flow
chart of each circuit, proceed to the circuit with the next highest number in the table to continue the
check.

TERMINALS OF ECM
1.ECM
Fig. 24: Identifying ECM Connector Terminals

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HINT:
Each ECM terminal's standard voltage is shown in the table below.
In the table, first follow the information under "Condition". Look under "Symbols (Terminal No.)" for the
terminals to inspected. The standard voltage between the terminals is shown under "Specific Condition".
Use the illustration above as a reference for the ECM terminals.

Fig. 25: Identifying ECM Terminals Reference Chart
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Waveform 1
Fig. 26: Identifying Waveform 1

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Reference:
WAVEFORM 1 REFERENCE TABLE
Waveform 2
TerminalSLT+ - SLT-
Tool setting5V/DIV, 1ms/DIV
Vehicle conditionEngine idle speed

Fig. 27: Identifying Waveform 2
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Reference:
WAVEFORM 2 REFERENCE TABLE
Waveform 3
TerminalSLU+ - SLU-
Tool setting5V/DIV, 1ms/DIV
Vehicle condition5th (lock-up) or 6th (lock-up) gear