Self-Diagnostic System: Pre-Check

1. Diagnosis System
   
   
   1. The engine control module (ECM) controls the function of the immobilizer on this vehicle. Data of the immobilizer or DTC can be read from the DLC3 of the vehicle. When a trouble occurs on the immobilizer, check that the engine warning light does not light up but DTC inspection is performed. When there seems to be trouble with the immobilizer, use the hand-held tester to check and trouble shoot it. See Fig 1.
   2. Check the DLC3. The vehicle's ECM uses ISO 9141-2 for communication. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 9141-2 format. See CONNECTOR IDENTIFICATION . See INSPECTING DLC3  table.
      NOTE: If your display shows UNABLE TO CONNECT TO VEHICLE when you have connected the cable of the hand-held tester to DLC3, turned the ignition switch ON and operated the hand-held tester, there is a problem on the vehicle side or tool side. If communication is normal when the tool is connected to another vehicle, inspect DLC3 on the original vehicle. If communication is still not possible when the tool is connected to another vehicle, the problem is probably in the tool itself.
      INSPECTING DLC3
      
      

      Terminal No.	Connection/Voltage Or Resistance	Condition
      7	Bus Line/Pulse Generation	During Transmission
      4	Chassis Ground - Body Ground/1 Ohm Or Less	Always
      16	Battery Positive - Body Ground/9-14 Volts	Always

2. Inspect Diagnosis (Normal Mode)
   
   See RETRIEVING DIAGNOSTIC TROUBLE CODES  and CLEARING DIAGNOSTIC TROUBLE CODES  .

Fig 1: Connecting Hand-Held Tester To DLC3

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