GSIC - Global Service Information Center

# ENGINE IMMOBILISER SYSTEM > DIAGNOSIS SYSTEM

DESCRIPTION

1. Engine immobiliser 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 immobiliser 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.

CHECK DLC3

HINT:

  The vehicle uses ISO 14230 (M-OBD) communication protocol. The terminal arrangement of the DLC3 complies with ISO 15031-03 and matches the ISO 14230 format.

Symbols (Terminals No.) | Terminal Description | Condition | Specified Condition
SIL (7) - SG (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 | Below 1 Ω

1. 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 display indicates that a communication error has occurred, there is a problem either with the vehicle or with the tester.

1. If communication is normal when the tester is connected to another vehicle, inspect the DLC3 of the original vehicle.
2. If communication is still 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.