ENGINE IMMOBILISER SYSTEM, Diagnostic DTC:B2780

DTC Code DTC Name
B2780 Push Switch / Key Unlock Warning Switch Malfunction

DESCRIPTION

This DTC is stored if the transponder key ECU assembly does not detect that the unlock warning switch assembly is on even when the ignition switch is ON. Under normal conditions, the unlock warning switch assembly is on when the ignition switch is ON.

DTC Code DTC Detection Condition Trouble Area DTC Output Confirmation Operation
B2780 The unlock warning switch assembly is not detected as being on when the ignition switch is ON (1 trip detection logic*).

  • Unlock warning switch assembly

  • Harness or connector

  • Transponder key ECU assembly

 Insert the key into the ignition key cylinder.

Vehicle Condition and Fail-safe Operation when Malfunction Detected
Vehicle Condition when Malfunction Detected Fail-safe Operation when Malfunction Detected
Engine cannot be started. -
Related Data List and Active Test
DTC Code Data List and Active Test
B2780 Key SW

WIRING DIAGRAM

A01DWWNE03

INSPECTION PROCEDURE

Note


  • When replacing the transponder key ECU assembly, refer to the Service Bulletin.

  • After performing repairs, perform the operation that fulfills the DTC output confirmation operation, and then confirm that no DTCs are output again.

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  2. CHECK FOR DTC


    1. Check for DTCs Click here.

      OK
      DTC B2780 is not output.

    NG

    INSPECT UNLOCK WARNING SWITCH ASSEMBLY Click here

    OK

    USE SIMULATION METHOD TO CHECK Click here

  3. INSPECT UNLOCK WARNING SWITCH ASSEMBLY


    1. A01DXBRE01
      Text in Illustration
      *a Pushed
      *b Not pushed

      Remove the unlock warning switch assembly.

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      1 - 2 Pushed Below 1 Ω
      Not pushed 10 kΩ or higher

    NG

    REPLACE UNLOCK WARNING SWITCH ASSEMBLY

    OK

  4. CHECK HARNESS AND CONNECTOR (UNLOCK WARNING SWITCH - TRANSPONDER KEY ECU AND BODY GROUND)


    1. Disconnect the U1 unlock warning switch assembly connector.

    2. Disconnect the T21 transponder key ECU assembly connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      U1-1 - T21-3 (KSW) Always Below 1 Ω
      U1-1 or T21-3 (KSW) - Body ground Always 10 kΩ or higher
      U1-2 - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE TRANSPONDER KEY ECU ASSEMBLY