Identifying condition LEXUS LS430 2003 Factory Repair Manual

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

Fig. 28: Identifying Waveform 3
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Reference:
WAVEFORM 3 REFERENCE TABLE
Waveform 4
TerminalSL2+ - SL2-
Tool setting5V/DIV, 1ms/DIV
Vehicle conditionEngine idle speed

Fig. 29: Identifying Waveform 4
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Reference:
WAVEFORM 4 REFERENCE TABLE
Waveform 5
TerminalSL1+ - SL1-
Tool setting5V/DIV, 1ms/DIV
Vehicle condition5th or 6th gear

Fig. 30: Identifying Waveform 5
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Reference:
WAVEFORM 5 REFERENCE TABLE
Waveform 6
TerminalNT+ - NT-
Tool setting1V/DIV, 2ms/DIV
Vehicle conditionEngine idle speed (P or N position)

Fig. 31: Identifying Waveform 6
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Reference:
WAVEFORM 6 REFERENCE TABLE
DIAGNOSIS SYSTEM
DESCRIPTION
When troubleshooting On-Board Diagnostic (OBD II) vehicles, the vehicle must be connected to the OBD II
scan tool (complying with SAE J1987). Various data output from the vehicle's ECM can then be read.
OBD II regulations require that the vehicle's on-board computer illuminates the Malfunction Indicator Lamp
(MIL) on the instrument panel when the computer detects a malfunction in:
1. The emission control s
ystem/components
TerminalSP2+ - SP2-
Tool setting2V/DIV, 20ms/DIV
Vehicle conditionVehicle speed 20 km/h (12 mph)

Fig. 34: Identifying DLC3 Terminals
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FREEZE FRAME DATA
Freeze frame data records the engine conditions (fuel system, calculated load, engine coolant temperature, fuel
trim, engine speed, vehicle speed, etc.) when a malfunction is detected. When troubleshooting, freeze frame
data can help determine if the vehicle was running or stopped, if the engine was warmed up or not, if the air/fuel
ratio was Lean or Rich, and other data from the time the malfunction occurred.
The hand-held tester records freeze frame data in five different instances: 1) 3 times before the DTC is set, 2)
once when the DTC is set, and 3) once after the DTC is set. These data can be used to simulate the vehicle's
condition around the time when the malfunction occurred. The data may help find the cause of the malfunction,
or
judge if the DTC is being caused by a temporary malfunction or not.

Fig. 36: Identifying DLC3 Terminals
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DLC3 REFERENCE TABLE
SymbolTerminal No.Name
Reference
terminal
ResultCondition
SIL7Bus "+" line5 - Signal groundPulse generationDuring
transmission
CG4Chassis groundBody groundBelow 1 ohmsAlways
SG5Signal groundBody groundBelow 1 ohmsAlways
BAT16Battery positiveBody ground11 to 14 VAlways
CANH6HIGH-level
CAN bus lineCANL54 to 69 ohmsIG switch OFF
CANH6HIGH-level
CAN bus lineBattery positive1 Mohms or
higherIG switch OFF
CANH6HIGH-level
CAN bus lineCG1 kohms or
higherIG switch OFF
CANL14LOW-level
CAN bus lineBattery positive1 Mohms or
higherIG switch OFF
CANL14LOW-level CG1 kohms or IG switch OFF