ENGINE IMMOBILISER SYSTEM (w/o Smart Key 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 key is in the ignition key cylinder. Under normal conditions, the unlock warning switch assembly is ON when the key is in the ignition key cylinder.

DTC No. DTC Detection Condition Trouble Area
B2780 "Unlock warning switch ON" is not detected when the key is in the ignition key cylinder.

  • Wire harness or connector

  • Unlock warning switch assembly

  • Transponder key ECU assembly

WIRING DIAGRAM

A011R4QE02

INSPECTION PROCEDURE

Note

If the transponder key ECU assembly is replaced, refer to Registration Click here.

PROCEDURE

  1. READ VALUE USING TECHSTREAM

    1. Connect the Techstream to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the Techstream on.

    4. Enter the following menus: Body Electrical / Immobiliser / Data List.

    5. Read the Data List according to the display on the Techstream.

      Immobiliser (Transponder Key ECU Assembly)
      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 in ignition key cylinder

      		 -
      OK
      On the Techstream screen, the item changes between ON and OFF according to the chart above.
    NG

    INSPECT UNLOCK WARNING SWITCH ASSEMBLY Click here

    OK

    REPLACE TRANSPONDER KEY ECU ASSEMBLY Click here

  2. INSPECT UNLOCK WARNING SWITCH ASSEMBLY

    1. Remove the unlock warning switch assembly Click here.

      A011V5OE04

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      1 - 2

      Pushed

      (Key set)

      		 Below 1 Ω
      1 - 2

      Free

      (Key removed)

      		 10 kΩ or higher
      Text in Illustration
      *a

      Component without harness connected

      (Unlock Warning Switch Assembly)
      *b Free
      *c Pushed
    NG

    REPLACE UNLOCK WARNING SWITCH ASSEMBLY Click here

    OK

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

    1. Disconnect the transponder key ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I19-3 (KSW) - I33-1 (UN+) Always Below 1 Ω
      I19-3 (KSW) - Body ground Always 10 kΩ or higher
      I33-2 (UN-) - Body ground Always Below 1 Ω
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE TRANSPONDER KEY ECU ASSEMBLY Click here