IMMOBILISER SYSTEM, Diagnostic DTC:B279A12

DTC Code DTC Name
B279A12 Engine Immobiliser System Circuit Short to Battery

DESCRIPTION

If the communication line (IMI - EFIO) between the hybrid vehicle control ECU and ID code box (immobiliser code ECU) is stuck high, the hybrid vehicle control ECU will store this DTC.

DTC No. Detection Item DTC Detection Condition Trouble Area Note
B279A12 Engine Immobiliser System Circuit Short to Battery The communication line (IMI - EFIO) between the hybrid vehicle control ECU and ID code box (immobiliser code ECU) is stuck high (1 trip detection logic*).

  • Wire harness or connector

  • ID code box (immobiliser code ECU)

  • Hybrid vehicle control ECU

DTC output confirmation operation:


  • Turn the power switch on (IG) and wait 6 seconds.

Vehicle Condition and Fail-safe Operation when Malfunction Detected
Vehicle Condition when Malfunction Detected Fail-safe Operation when Malfunction Detected
Hybrid control system cannot be started Hybrid control system cannot be started
Related Data List and Active Test
DTC No. Data List and Active Test
B279A12 -

WIRING DIAGRAM

B004PFUE13
*a ID Code Box (Immobiliser Code ECU)
*b Hybrid Vehicle Control ECU

CAUTION / NOTICE / HINT

Note


  • When using the GTS with the power switch off, connect the GTS to the DLC3 and turn a courtesy light switch on and off at intervals of 1.5 seconds or less until communication between the GTS and the vehicle begins. Then select Model Code "KEY REGIST" under manual mode and enter the following menus: Body Electrical / Entry&Start(CAN). While using the GTS, periodically turn a courtesy light switch on and off at intervals of 1.5 seconds or less to maintain communication between the GTS and the vehicle.

  • When replacing the hybrid vehicle control ECU or ID code box (immobiliser code ECU), refer to Service Bulletin.

  • After performing repairs, confirm that no DTCs are output by performing "DTC Output Confirmation Operation."

Tech Tips

When DTC B279A12 and a certification ECU (smart key ECU assembly) DTC are output simultaneously, first perform troubleshooting for the certification ECU (smart key ECU assembly) DTC.

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTCs.

      Click here


      Powertrain > Hybrid Control > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  2. CHECK FOR DTC


    1. Turn the power switch on (IG) and wait 10 seconds.

    2. Check for DTCs.

      Click here


      Powertrain > Hybrid Control > Trouble Codes

      Tech Tips

      If DTCs other than DTC B279A12 are output, troubleshoot those DTCs first.

      Result
      Result Proceed to
      Only DTC B279A12 is output A
      DTC B279A12 and other DTCs are output B

    B

    GO TO DIAGNOSTIC TROUBLE CODE CHART Click here

    A

  3. CHECK CONNECTION OF CONNECTOR


    1. Turn the power switch off.

    2. Check that the connectors are properly connected to the hybrid vehicle control ECU and ID code box (immobiliser code ECU).

      OK
      Connectors are properly connected.
      Result
      Proceed to
      OK
      NG

    NG

    CONNECT CONNECTORS PROPERLY

    OK

  4. CHECK HARNESS AND CONNECTOR (ID CODE BOX (IMMOBILISER CODE ECU) - HYBRID VEHICLE CONTROL ECU)


    1. Disconnect the F19 ID code box (immobiliser code ECU) connector.

    2. Disconnect the F3 hybrid vehicle control ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F19-4 (EFIO) - F3-10 (IMI) Always Below 1 Ω
      F19-4 (EFIO) or F3-10 (IMI) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. REPLACE HYBRID VEHICLE CONTROL ECU


    1. Replace the hybrid vehicle control ECU with a new one.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  6. CLEAR DTC


    1. Clear the DTCs.

      Click here


      Powertrain > Hybrid Control > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  7. CHECK FOR DTC


    1. Check for DTCs.


      Powertrain > Hybrid Control > Trouble Codes

      Tech Tips

      Before checking for DTCs, perform the "DTC Output Confirmation Operation" procedure.

      OK
      DTC B279A12 is not output.
      Result
      Proceed to
      OK
      NG

    OK

    END (HYBRID VEHICLE CONTROL ECU WAS DEFECTIVE)

    NG

    REPLACE ID CODE BOX (IMMOBILISER CODE ECU)