Diagnosis System

WARNING: This page is about a different car, the 2005 Lexus RX 330. However, it is still accessible from the selected car via links, so may be relevant.

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 AND SPECIFIED CONDITION CHART

Tester Connection	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 screen displays UNABLE TO CONNECT TO VEHICLE after you have connected the cable of the hand-held tester to the DLC3, turned the ignition switch ON and used the hand-held 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.
Standard: 11 to 14 V

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