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Diagnosis System

WARNING: This page is about a different car, the 2006 Scion tC. However, it is still accessible from the selected car via links, so may be relevant.
  1. DESCRIPTION 
    1. Engine immobilizer system data and Diagnostic Trouble Codes (DTCs) can be read through the vehicle's Data Link Connector 3 (DLC3). In some cases, a malfunction may be occurring in the immobilizer system even though the security indicator is not illuminated. When the system seems to be malfunctioning, use the intelligent tester to check for malfunctions and perform repairs.
  2. CHECK DLC3 

HINT:

The vehicle uses ISO 9141-2 communication protocol.

The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 9141-2 format.

Fig 1: Identifying DLC3 Connector Terminals
G04224078Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
TERMINALS DESCRIPTION - SPECIFIED CONDITIONS

Symbols (Terminal No.) Terminal Description Condition Specified Condition
SIL (7) - SF (5) Bus "+" line During transmission Pulse generation
BAT (16) - Body ground Battery positive Always 10 to 14 V
CG (4) - Body ground Chassis ground Always Below 1 Ω
SG (5) - Body ground Signal ground Always

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 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 with the tester.

Fig 2: Connecting Intelligent Tester To DLC3
G04224079Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002