Diagnosis System

DESCRIPTION
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 intelligent tester to check for malfunctions and perform repairs.
  
  Fig 1: Identifying DLC3 Connector Terminals (CANL & BAT)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

CHECK DLC3

The ECU uses ISO 15765-4 communication. The terminal arrangement of the DLC3 complies with SAE J 1962 and matches the ISO 15765-4 format.

Fig 2: Connecting Cable Of Intelligent Tester To DLC3

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

CONNECTOR TERMINAL RESISTANCE SPECIFICATION

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

10 to 14 V

CANH (6) - CANL (14)

CAN bus line

Ignition Switch OFF⁽¹⁾

54 to 69 Ω

CANH (6) - CG (4)

HIGH-level CAN bus line

Ignition Switch OFF⁽¹⁾

200 Ω or more

CANL (14) - CG (4)

LOW-level CAN bus line

Ignition Switch OFF⁽¹⁾

200 Ω or more

CANH (6) - BAT (16)

HIGH-level CAN bus line

Ignition Switch OFF⁽¹⁾

6 kΩ or more

CANL (14) - BAT (16)

LOW-level CAN bus line

Ignition Switch OFF⁽¹⁾

6 kΩ or more

NOTE:

⁽¹⁾	Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the ignition switch, any other switches or the door.

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

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