General Information

A large number of ECU controlled systems are used in this vehicle In general, ECU controlled systems are considered to be very intricate, requiring a high level of technical knowledge to troubleshoot However, most problem checking procedures only involve inspecting the ECU controlled system circuits one by one. An adequate understanding of the system and a basic knowledge of electricity is enough to perform effective troubleshooting, accurate diagnosis and necessary repairs

(For using the Techstream*)

HINT

*. The Techstream is the name for the diagnostic tester in North America

• Before using the Techstream, read the operator's service information thoroughly
• If the Techstream cannot communicate with the ECU controlled systems when connected to the DLC3 with the engine switch on (IG) and the Techstream on, there is a problem on the vehicle side or the Techstream side
  1. If communication is possible when the Techstream is connected to another vehicle, inspect the diagnosis data link line (Bus (+) line), CANH and CANL lines, and the power circuits for the vehicle ECUs
  2. If communication is still not possible when the Techstream is connected to another vehicle, the problem is probably in the Techstream itself Perform the Self Test procedure outlined in the Techstream operator's service information.

1. DESCRIPTION 
   1. Each system data and the Diagnostic Trouble Codes (DTCs) 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
2. CHECK DLC3 
   1. The vehicle ECUs use ISO 15765-4 communication protocol The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 15765-4 format.
      Fig 1: Identifying DLC3 Terminals

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      RESISTANCE SPECIFICATION
      
      

      Symbol	Terminal No.	Name	Reference Terminal	Result	Condition
      SIL	7	Bus "+" line	5 - Signal ground	Pulse generation	During transmission
      CG	4	Chassis ground	Body ground	1 Ω or less	Always
      SG	5	Signal ground	Body ground	1 Ω or less	Always
      BAT	16	Battery positive	Body ground	1 Ω or less	Always
      CANH	6	CAN "High" line	14 - CANL	54 to 69 Ω	Engine switch off(1)
      			Battery positive	6 kΩ or higher	Engine switch off(1)
      			4 - CG	200 Ω or higher	Engine switch off(1)
      CANL	14	CAN "Low" line	Battery positive	6 kΩ or higher	Engine switch off(1)
      			4 - CG	200 Ω or higher	Engine switch off(1)
      (1) Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the engine switch, any other switches, or the doors.

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