ENGINE IMMOBILISER SYSTEM (w/ Entry and Start System) > DIAGNOSIS SYSTEM

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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 light is not illuminated. When the system seems to be malfunctioning, use the intelligent tester to check for malfunctions and perform repairs.


CHECK DLC3
The vehicle's ECU uses the ISO 15765-4 communication protocol. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 15765-4 format.
If the result is not as specified, the DLC3 may have a malfunction. Repair or replace the harness and connector.
H100769E16

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
Engine switch off*
54 to 69 Ω
CANH (6) - Battery positive
HIGH-level CAN bus line
Engine switch off*
6 kΩ or higher
CANH (6) - CG (4)
HIGH-level CAN bus line
Engine switch off*
200 Ω or higher
CANL (14) - Battery positive
LOW-level CAN bus line
Engine switch off*
6 kΩ or higher
CANL (14) - CG (4)
LOW-level CAN bus line
Engine switch off*
200 Ω or higher

NOTICE:
*: Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the engine switch, other switches or doors.

HINT:
B127990E01
Connect the cable of the intelligent tester to the DLC3, turn the engine switch on (IG) and attempt to use the intelligent tester. If the screen displays UNABLE TO CONNECT TO VEHICLE, a problem exists in the vehicle side or the tester side.
If the communication is normal when the tester is connected to another vehicle, inspect the DLC3 on the original vehicle.
If the 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.