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 does not detect that the unlock warning switch is on even when the ignition switch is ON. Under normal conditions, the unlock warning switch is on when the ignition switch is ON.

DTC Code DTC Detection Condition Trouble Area
B2780 The unlock warning switch on is not detected as being on when the ignition switch is ON.

  • Transponder key ECU

  • Unlock warning switch

  • Harness or connector

WIRING DIAGRAM

A003C14E06

INSPECTION PROCEDURE

Tech Tips

When the transponder key ECU is replaced, reregister the ECU - ECM communication ID.

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

    READ VALUE USING INTELLIGENT TESTER (UNLOCK WARNING SWITCH) Click here

    OK

    USE SIMULATION METHOD TO CHECK Click here

  3. READ VALUE USING INTELLIGENT TESTER (UNLOCK WARNING SWITCH)


    1. Use the Data List to check if the unlock warning switch is functioning properly.

      OK
      ON (the key is inserted in the ignition key cylinder) appears on the screen.
      Immobiliser
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Key SW Unlock warning switch signal / ON or OFF

      ON: Key in ignition key cylinder

      OFF: No key inserted in ignition key cylinder

      		 -

    NG

    INSPECT UNLOCK WARNING SWITCH Click here

    OK

    REPLACE TRANSPONDER KEY ECU

  4. INSPECT UNLOCK WARNING SWITCH

    A003B5KE04

    1. Remove the unlock warning switch 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 Switch pushed Below 1 Ω
      Switch not pushed 10 kΩ or higher

    NG

    REPLACE UNLOCK WARNING SWITCH Click here

    OK

  5. CHECK HARNESS AND CONNECTOR (UNLOCK WARNING SWITCH - BODY GROUND)

    A003CLKE11
    Text in Illustration
    *1

    Front view of wire harness connector

    (to Unlock Warning Switch)

    1. Disconnect the D99 switch connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D99-2 - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. CHECK HARNESS AND CONNECTOR (UNLOCK WARNING SWITCH - TRANSPONDER KEY ECU)

    A003DE8E13
    Text in Illustration
    *1

    Front view of wire harness connector

    (to Unlock Warning Switch)
    *2

    Front view of wire harness connector

    (to Transponder Key ECU)

    1. Disconnect the D99 switch connector.

    2. Disconnect the D102 ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D102-3 (KSW) - D99-1 Always Below 1 Ω
      D102-3 (KSW) or D99-1 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE TRANSPONDER KEY ECU