ENGINE IMMOBILISER SYSTEM(w/o Entry and Start 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*).

  • Transponder key ECU assembly

  • Unlock warning switch assembly

  • Harness or connector

 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

A005JACE03
*a UNLOCK WARNING SWITCH ASSEMBLY
*b TRANSPONDER KEY ECU ASSEMBLY

CAUTION / NOTICE / HINT

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.

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

  3. INSPECT UNLOCK WARNING SWITCH ASSEMBLY


    1. A005HR4E06
      Text in Illustration
      *a

      Component without harness connected

      (Unlock Warning Switch Assembly)

      Remove the unlock warning switch assembly Click here.

    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 Click here

    OK

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


    1. Disconnect the F54 transponder key ECU assembly connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      F15-1 - F54-3 (KSW) Always Below 1 Ω
      F15-2 - Body ground Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      F15-1 or F54-3 (KSW) - Body ground Always 10 kΩ or higher

    OK

    REPLACE TRANSPONDER KEY ECU ASSEMBLY

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR