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*).

  • Transponder key ECU assembly

  • Unlock warning switch assembly

  • Harness or connector

 Insert the key into the ignition key cylinder.

WIRING DIAGRAM

A01CH7DE09

INSPECTION PROCEDURE

Note


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

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

PROCEDURE


  1. INSPECT UNLOCK WARNING SWITCH ASSEMBLY


    1. A01CHQ6E08
      Text in Illustration
      *a Free
      *b Pushed

      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 Condition Specified Condition
      1 (UN+) - 2 (UN-) Pushed Below 1 Ω
      Not pushed 10 kΩ or higher

    NG

    REPLACE UNLOCK WARNING SWITCH ASSEMBLY Click here

    OK

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


    1. Disconnect the U1 unlock warning switch connector.

    2. Disconnect the T18 transponder key ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      U1-1 (UN+) - T18-3 (KSW) Always Below 1 Ω
      U1-2 (UN-) - Body ground Always Below 1 Ω
      U1-1 (UN+) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE TRANSPONDER KEY ECU ASSEMBLY