ENTRY AND START SYSTEM, Diagnostic DTC:B2278

DTC Code DTC Name
B2278 Engine Switch Circuit Malfunction

DESCRIPTION

This DTC is output when: 1) a malfunction is detected between the main body ECU and the engine switch; or 2) either of the switches inside the engine switch is malfunctioning.

DTC Code Detection Condition Trouble Area
B2278 Communication is abnormal between main body ECU and engine switch or engine switch is defective

  • Main body ECU

  • Engine switch

  • Harness or connector

WIRING DIAGRAM

A001FJSE04
*a Engine Switch
*b Main Body ECU

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER (START SWITCH 1 AND 2)


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

      Main Body
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Start Switch 1 Start Switch 1/ON or OFF

      ON: Engine switch on (IG)

      OFF: Engine switch off

      		 -
      Start Switch 2 Start Switch 2/ON or OFF

      ON: Engine switch on (IG)

      OFF: Engine switch off

      		 -
      OK
      ON appears on the screen.

    NG

    INSPECT ENGINE SWITCH Click here

    OK

  2. CHECK ENGINE SWITCH (SWITCH CONDITION)


    1. Ensure the key is inside the cabin.

    2. Check that the power source mode changes as shown below each time the engine switch is pushed.

      OK
      off → on (ACC) → on (IG) → off

    OK

    SYSTEM IS OK

    NG

    GO TO POWER SOURCE MODE DOES NOT CHANGE Click here

  3. INSPECT ENGINE SWITCH

    A001FIDE01
    *1 Component without harness connected: (Engine Switch)

    1. Remove the engine switch Click here.

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

      Standard resistance
      Tester Connection Switch Condition Specified Condition
      7 (SS1) - 5 (GND) Pushed Below 1 Ω
      2 (SS2) - 5 (GND) Pushed Below 1 Ω
      7 (SS1) - 5 (GND) Not pushed 10 kΩ or higher
      2 (SS2) - 5 (GND) Not pushed 10 kΩ or higher

    NG

    REPLACE ENGINE SWITCH Click here

    OK

  4. CHECK HARNESS AND CONNECTOR (ENGINE SWITCH - MAIN BODY ECU AND BODY GROUND)

    A0019LKE03
    *1 Front view of wire harness connector: (to Engine Switch)
    *2 Front view of wire harness connector: (to Main Body ECU)

    1. Disconnect the L36 engine switch connector.

    2. Disconnect the L13 main body ECU connector.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      L36-7 (SS1) - L13-17 (SSW1) Always Below 1 Ω
      L36-2 (SS2) - L13-16 (SSW2) Always Below 1 Ω
      L36-5 (GND) - Body ground Always Below 1 Ω
      L36-7 (SS1) or L13-17 (SSW1) - Body ground Always 10 kΩ or higher
      L36-2 (SS2) or L13-16 (SSW2) - Body ground Always 10 kΩ or higher

    OK

    REPLACE MAIN BODY ECU

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR