Diagnosis System
- DESCRIPTION
The gateway ECU sets a diagnosis trouble code (DTC) if a malfunction occurs in the multiplex communication network (MPX). The Techstream 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 CONDITIONSymbols (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 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 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 Techstream is connected to another vehicle, inspect the DLC3 on the original vehicle.
If communication is still not possible when the Techstream is connected to another vehicle, the problem is probably in the Techstream itself. Consult the Service Department listed in the Techstream's instruction manual.