Diagnosis System

1. The transponder key ECU controls the vehicle's immobilizer system functions. Immobilizer system data and the DTCs can be read through the vehicle's DLC3.

   In some cases, a malfunction may be occurring in the immobilizer system even though the security indicator lamp is not illuminated. When the system seems to be malfunctioning, use the hand-held tester to check for a malfunction and perform repairs.

HINT:

The vehicle uses ISO 9141-2 communication protocol. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 9141-2 format.

Fig 1: Checking DLC3

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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 hand-held 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.

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

Fig 2: Connecting Cable Of Hand-Held Tester To DLC3

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Standard: 11 to 14 V 

1. If the voltage is below 11 V, recharge the battery before proceeding.