Diagnosis System

DESCRIPTION

a. DIAGNOSIS SYSTEM
When troubleshooting is conducted for Multiplex OBD (M-OBD) vehicles, the only difference from the usual troubleshooting procedure is that the LEXUS hand-held tester is to be connected to read off various data output from the vehicle's skid control ECU.
The skid control ECU records the corresponding DTC when the computer detects a malfunction in the computer itself or its circuit.
To check DTC, connect a LEXUS hand-held tester to DLC3 on the vehicle. The LEXUS hand-held tester enables you to erase DTC and activate the several solenoids and actuators, and check freeze frame data and various forms on skid control data.







b. DATA LINK CONNECTOR 3 (DLC3)
The skid control ECU uses ISO 14230 for communication. The terminal arrangement of DLC3 complies with SAEJ1962 and matches the ISO 14230 format.

HINT: If the display shows "UNABLE TO CONNECT TO VEHICLE" when the LEXUS hand-held tester cable is connected to DLC3, the ignition switch is turned ON and the LEXUS hand-held tester is operated, there is a problem on the vehicle side or the tester side.
- If communication is normal when the tester is connected to another vehicle, inspect DLC3 on the original vehicle.
- If communication is still not possible when the tester is connected to another vehicle, the problem is probably in the tester itself, so consult the Service Department listed in the tester's Operator's Manual.