Lexus SC300 / Lexus SC400. Manual - part 7

[4] DIAGNOSTIC CODE CHART
The inspection procedure is shown in the table below. This table permits efficient and accurate troubleshooting
using the trouble codes displayed in the diagnostic code check. Proceed with troubleshooting in accordance
with the inspection procedure given in the diagnostic chart corresponding to the trouble codes displayed. The
engine diagnostic code chart is shown below as an example.

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How to Troubleshoot ECU Controlled Systems

[5] MATRIX CHART OF PROBLEM SYMPTOMS
The suspect circuits or parts for each problem symptom are shown in the table below. Use this table to trouble-
shoot the problem when a ”Normal” code is displayed in the diagnostic code check but the problem is still occur-
ring. Numbers in the table indicate the inspection order in which the circuits or parts should be checked.
HINT: When the problem is not detected by the diagnostic system even though the problem symptom is present,
it is considered that the problem is occurring outside the detection range of the diagnostic system, or that the
problem is occurring in a system other than the diagnostic system.

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How to Troubleshoot ECU Controlled Systems

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6 CIRCUIT INSPECTION
How to read and use each page is shown below.

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How to Troubleshoot ECU Controlled Systems

Location of Connectors in Engine Compartment

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Location of connectors
This diagram shows the wire harnesses and connectors used in one system.
The connector shows the harness side connector, so when checking the part side connector (sensor, ac-
tuator, etc.), be careful not to mistake the terminal positions.

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How to Troubleshoot ECU Controlled Systems

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