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 is not detected as being on when the ignition switch is ON.

  • Transponder key ECU

  • Unlock warning switch

  • Harness or connector

WIRING DIAGRAM

E146342E12

CAUTION / NOTICE / HINT

Note:

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

PROCEDURE

  1. CLEAR DTC

    1. Clear the DTCs (Click here).

  2. CHECK FOR DTC

    1. Check for DTCs (Click here).

      OK

      DTC B2780 is not output.

    USE SIMULATION METHOD TO CHECK

    (Click here)

  3. INSPECT UNLOCK WARNING SWITCH

    1. E146811E09

      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

      Pushed

      Below 1 Ω

      Not pushed

      10 kΩ or higher

    REPLACE UNLOCK WARNING SWITCH

    (Click here)

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

    1. U122344E02

      Disconnect the H7 switch connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      H7-2 - Body ground

      Always

      Below 1 Ω
      Table 1. Text in Illustration

      *1

      Front view of wire harness connector

      (to Unlock Warning Switch)

    REPAIR OR REPLACE HARNESS OR CONNECTOR

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

    1. U122346E02

      Disconnect the H7 switch connector.

    2. Disconnect the H110 ECU connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      H110-3 (KSW) - H7-1

      Always

      Below 1 Ω

      H110-3 (KSW) or H7-1 - Body ground

      Always

      10 kΩ or higher
      Table 2. 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)

    REPLACE TRANSPONDER KEY ECU

    REPAIR OR REPLACE HARNESS OR CONNECTOR