Description of On-Board Diagnostics

DIAGNOSIS SYSTEM




a. Description
ECM controls the function of immobilizer on this vehicle. Data of the immobilizer or DTC can be read form DLC3 of the vehicle. When a trouble occurs on immobilizer, MIL does not light on but DTC inspection is performed. Therefore when there seems to be a trouble on immobilizer, use LEXUS hand-held tester or SST to check and troubleshoot it.







b. Inspect the DLC3.
The vehicle's ECM uses ISO 9141-2 for communication. The terminal arrangement of DLC3 complies with SAE J1962 and matches the ISO 9141-2 format.

HINT: If your display shows "UNABLE TO CONNECT TO VEHICLE" when you have connected the cable of OBD II scan tool or LEXUS hand-held tester to DLC3, turned the ignition switch ON and operated the scan tool, there is a problem on the vehicle side or tool side.

- If communication is normal when the tool is connected to another vehicle, inspect DLC3 on the original vehicle.
- If communication is still not possible when the tool is connected to another vehicle, the problem is probably in the tool itself, so consult the Service Department.