Diagnosis System

ENGINE IMMOBILIZER SYSTEM:

DIAGNOSIS SYSTEM

1. DESCRIPTION
(a) The transponder key ECU controls the vehicle's immobilizer system functions. Immobilizer system data and Diagnostic Trouble Codes (DTCs) can be read using Techstream after it is attached to the Data Link Connector 3 (DLC3). In some cases, a malfunction may be occurring in the immobilizer system even though the security indicator light is not illuminated.
If the system seems to be malfunctioning, use Techstream to inspect the operation of the system before performing repairs.
2. CHECK DLC3






(a) The vehicle's ECU uses ISO 15765-4 for communication protocol. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 15765-4 format.





NOTE: *: 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 doors.
If the result is not as specified, the DLC3 may have a malfunction. Repair or replace the harness and connector.

(b) Connect the cable of Techstream to the DLC3, turn the ignition switch to the ON position and attempt to use Techstream. If the screen displays a communication error message, a problem exists in the vehicle side of the tester side.
HINT:
- If communication is normal when the tool is connected to another vehicle, inspect the DLC3 on the original vehicle.
- If communication is still impossible when the tool is connected to another vehicle, the problem is probably in the tool itself. Consult the Service Department listed in the tool's instruction manual.