Diagnosis System

DIAGNOSIS SYSTEM




a. As shown in the following illustration, each ECU of this vehicle is connected by communication bus and it transmits each signal by communication. This communication bus is self-diagnosed by Body No. 1 ECU and it memorizes DTC when it detects communication stop to ECU or communication bus +B short or GND short. There is a possibility that Body No. 1 ECU cannot self-diagnose accurately unless it doesn't work normal. So, please note that the troubleshooting of Body Electrical System should be done after confirming if Body No. 1 ECU and Open door indicator works normal by 2 "BASIC INSPECTION" described later.




b. If DTC of ECU communication stop is output, there is a possibility of connector disconnection or 2 communication buses open. It will not become abnormal with only 1 communication bus open.




c. If 2 communication buses are open at the position as shown in the illustration, DTC of ECU communication stop between those 2 buses is output.