Diagnosis System

Fig 1: Identifying DLC3 Connector

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 intelligent 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.

1. Primary check
   1. Turn the ignition switch to the LOCK position.

      Wait at least 2 seconds, then turn the ignition switch to the ON position. The SRS warning light comes on for approximately 6 seconds and the diagnosis of the SRS airbag system (including the seat belt) is performed.

      HINT:

      If trouble is detected during the primary check, the SRS warning light remains on or blinks even after the primary check period (approximately 6 seconds) has elapsed.

2. Constant check
   1. After the primary check, the center airbag sensor assembly activates the SRS airbag system and constantly monitors it for trouble.

      HINT:

      If malfunctions are detected during the constant check, the center airbag sensor functions as follows:

      • The SRS warning light comes on or blinks.
      • The SRS warning light comes on, and then goes off. This blinking pattern indicates the source voltage drop. The SRS warning light goes off 10 seconds after the source voltage returns to normal.
3. Review
   1. When the airbag system is normal:

      The SRS warning light comes on only during the primary check period (for approximately 6 seconds after the ignition switch is turned to the ON position).

   2. When the airbag system has trouble:
      • The SRS warning light remains on or blinks even after the primary check period has elapsed.
      • The SRS warning light goes off after the primary check, but comes on or blinks again during the constant check.
      • The SRS warning light does not come on when turning the ignition switch from the LOCK to ON position.

      HINT:

      The center airbag sensor assembly keeps the SRS warning light ON if the airbag has been deployed.

1. Turn the ignition switch to the ON position, and check that the SRS warning light comes on for approximately 6 seconds (primary check).
2. Check that the SRS warning light goes off approximately 6 seconds after the ignition switch is turned to the ON position (constant check).

   HINT:

   When any of the following symptoms occurs, refer to the "Problem Symptoms Table" (See PROBLEM SYMPTOMS TABLE  ).

   Fig 2: Identifying SRS Warning Light

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   • When the SRS warning light comes on occasionally even after the primary check period has elapsed, an open or short in the SRS warning light circuit is suspected.
   • When the SRS warning light comes on even when the ignition switch is in the LOCK position, trouble in the power source or combination meter assembly is suspected.
   • When the ignition switch is turned from the LOCK to ON position, the SRS warning light does not come on.