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

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DESCRIPTION

  1. The certification ECU (smart key ECU assembly) and ECM control the vehicle engine immobiliser system functions. Engine immobiliser system data and Diagnostic Trouble Codes (DTCs) can be read through the vehicle Data Link Connector 3 (DLC3).
    In some cases, a malfunction may be occurring in the engine 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


    A082779E65

  1. The vehicle ECU uses the ISO 15765-4 for communication protocol. The terminal arrangement of the DLC3 complies with ISO 15031-3 and matches the ISO 15765-4 format.

    Symbols (Terminal No.)
    		Terminal Description
    		Condition
    		Specified Condition
    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
    		9 to 14 V
    CANH (6) - CANL (14)
    		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

    HINT:
    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 a communication error message, a problem exists on either 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 impossible when the tester is connected to another vehicle, the problem is probably in the tester itself. Consult the Service Department listed in the tester instruction manual.

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

INSPECT BATTERY VOLTAGE

  1. Measure the battery voltage.

    Standard Voltage:
    11 to 14 V
    If the voltage is below 11 V, recharge or replace the battery.