Diagnosis System

DIAGNOSIS SYSTEM

Inspect the DLC3.

HINT:

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

Fig 1: Identifying DLC3 Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

TESTER CONNECTION SPECIFIED CONDITION CHART

Terminal No.	Condition	Specified Condition
7 (Bus + line) - 5 (Signal ground)	During communication	Pulse generation
4 (Chassis ground) - Body ground	Constant	Below 1 Ω
5 (Signal ground) - Body ground	Constant	Below 1 Ω
16 (B+) - Body ground	Constant	9 to 14 V

HINT:

If the display shows UNABLE CONNECT TO VEHICLE when you have connected the cable of the intelligent tester to the DLC3, turned the ignition switch ON and operated the intelligent tester, there is a problem on the vehicle side or tester side.

If communication is normal when the tester is connected to another vehicle, inspect the DLC3 of the original vehicle.
If communication is still impossible 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 instruction manual.

Check the battery voltage.
Battery voltage: 11 to 14 V

If voltage is below 11V, recharge the battery before proceeding.