LS 460 RWD V8-4.6L (1UR-FSE) (2010)
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7. CIRCUIT INSPECTION
A description of the main areas of each circuit inspection is below.
General Information
INTRODUCTION: HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS: GENERAL INFORMATION
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A large number of ECU controlled systems are used in the LEXUS LS460L / LS460. In general, ECU controlled systems are considered to be very
intricate, requiring a high level of technical knowledge to troubleshoot. However, most problem checking procedures only involve inspecting the
ECU controlled system's circuits one by one. An adequate understanding of the system and a basic knowledge of electricity is enough to perform
effective troubleshooting, accurate diagnoses and necessary repairs.
1. TROUBLESHOOTING PROCEDURES
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The troubleshooting procedures consist of diagnosis procedures for when a DTC is stored and diagnosis procedures for when no DTC is
stored. The basic idea is explained in the following table.
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Vehicle systems are complex and use many ECUs that are difficult to inspect independently. Therefore, a process of elimination is used, where
components that can be inspected individually are inspected, and if no problems are found in these components, the related ECU is identified
as the problem and replaced.
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It is extremely important to ask the customer about the environment and the conditions present when the problem occurred (Customer Problem
Analysis). This makes it possible to simulate the conditions and confirm the symptom. If the symptom cannot be confirmed or the DTC does
not recur, the malfunctioning part may not be identified using the troubleshooting procedure, and the ECU for the related system may be
replaced even though it is not defective. If this happens, the original problem will not be solved.
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In order to prevent endless expansion of troubleshooting procedures, the troubleshooting procedures are written with the assumption that
multiple malfunctions do not occur simultaneously for a single problem symptom.
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To identify the malfunctioning part, troubleshooting procedures narrow down the target by separating components, ECUs and wire harnesses
