General Information

A large number of ECU controlled systems are used in this vehicle. In general, the ECU controlled system is considered to be a very intricate system requiring high level of technical knowledge and expert skill to troubleshoot. The fact is, however, that if you proceed to inspect the circuits one by one, troubleshooting of these systems is not complex. If you have adequate understanding of the system and basic knowledge of electricity, accurate diagnosis and necessary repair can be performed to locate and fix the problem. This manual is designed through emphasis of the above standpoint to help service technicians perform an accurate and effective troubleshooting, and is compiled for the following major ECU controlled systems.

The troubleshooting procedure and how to make use of it are described on the following pages.

Fig 1: Trouble Shooting Procedure Table

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FOR USING OBDII SCAN TOOL OR HAND-HELD TESTER 

HINT:

• Before using the scan tool or tester, the scan tool's instruction book or tester's operator manual should be read thoroughly.
• If the scan tool or tester cannot communicate with the ECU controlled systems when you have connected the cable of the scan tool or tester to the DLC3, turned the ignition switch ON and operated the scan tool, there is a problem on the vehicle side or tool side.
  1. If the communication is normal when the tester is connected to another vehicle, inspect the diagnosis data link line (Bus outline) or ECU power circuit of the vehicle.
  2. If the communication is still impossible when the tester is connected to another vehicle, the problem is probably in the tester itself, so perform the Self Test procedures outlined in the Tester Operator's Manual.