Diagnosis System

WARNING: This page is about a different car, the 2007 Toyota Prius. However, it is still accessible from the selected car via links, so may be relevant.

DESCRIPTION
The gateway ECU sets a diagnosis trouble code (DTC) if a malfunction occurs in the multiplex communication network (MPX). The intelligent tester allows the DTC to be displayed when the tester is connected to the DLC3.

DLC3

The vehicle's ECU uses the ISO 15765-4 communication protocol. The terminal arrangement of the DLC3 complies with ISO 15031-3 and matches the ISO 15765-4 format.

TERMINALS DESCRIPTION AND SPECIFIED CONDITION

Symbols (Terminal No.)	Terminal Description	Condition	Specified condition
SIL (7) - SG (5)	Bus "+" line	During transmission	Pulse generation
CG (4) - Body ground	Chassis ground	Always	Below 1 Ω
SG (5) - Body ground	Signal ground	Always	Below 1 Ω
BAT (16) - Body ground	Battery positive	Always	11 to 14 V
CANH (6) - CANL (14)	HIGH-level CAN bus line	Power switch OFF	54 to 69 Ω
CANH (6) - Body ground	HIGH-level CAN bus line	Power switch	OFF 1 MΩ or higher
CANH (6) - CG (4)	HIGH-level CAN bus line	Power switch OFF	1 kΩ or higher
CANL (14) - Body ground	LOW-level CAN bus line	Power switch	OFF 1 MΩ or higher
CANL (14) - CG (4)	LOW-level CAN bus line	Power switch	OFF 1 kΩ or higher

Fig 1: Identifying DLC3 Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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 intelligent tester (with CAN VIM) to the DLC3, turn the power switch ON (IG) and attempt to use the tester. If the screen displays the message UNABLE TO CONNECT TO VEHICLE, there is a problem either with the vehicle or the tester. If communication is normal when the intelligent tester is connected to another vehicle, inspect the DLC3 on the original vehicle.

Fig 2: Connecting Intelligent Tester To DLC3

If communication is still not possible when the tester is connected to another vehicle, the problem is probably in the tester itself. Consult the Service Department listed in the tester's instruction manual.