Diagnosis System

1. The defogger system data can be read from the Data Link Connector 3 (DLC3) of the vehicle. When the system seems to be malfunctioning, use the Techstream to check for malfunctions and perform repairs.

1. The vehicle uses the ISO 15765-4 for communication protocol. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 15765-4 format.
   Fig 1: Identifying DLC3 Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard voltage 

   DLC3 TERMINALS REFERENCE
   
   

   Symbol (Terminal No.)	Terminal Description	Condition	Specified Condition
   SIL (7) - SG (5)	Bus "+" line	During transmission	Pulse generation
   BAT (16) - Body ground	Battery positive	Always	10 to 14 V

   Standard resistance 

   DLC3 TERMINALS REFERENCE
   
   

   Symbol (Terminal No.)	Terminal Description	Condition	Specified Condition
   CG (4) - Body ground	Chassis ground	Always	Below 1 Ω
   SG (5) - Body ground	Signal ground	Always	Below 1 Ω
   CANH (6) - CANL (14)	CAN bus line	Engine switch off	54 to 67 Ω
   CANH (6) - Body positive (+)	HIGH-level CAN bus line	Engine switch off	1 MΩ or higher
   CANH (6) - CG (4)	HIGH-level CAN bus line	Engine switch off	3 MΩ or higher
   CANL (14) - Body positive (+)	LOW-level CAN bus line	Engine switch off	1 MΩ or higher
   CANL (14) - CG (4)	LOW-level CAN bus line	Engine switch off	3 MΩ or higher

   If the result is not as specified, the DLC3 may have a malfunction. Repair or replace the harness and connector.

   HINT:

   Connect the cable of the Techstream to the DLC3, turn the engine switch on (IG) and attempt to use the Techstream. If the display indicates that a communication error has occurred, there is a problem either with the vehicle or with the Techstream.

   • If communication is normal when the tester is connected to another vehicle, inspect the DLC3 of the original vehicle.
   • If communication is still not possible when the tester is connected to another vehicle, the problem may be in the Techstream itself. Consult the Service Department listed in the tester's instruction manual.

Standard voltage: 

11 to 14 V 

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