ENTRY AND START SYSTEM (for Start Function), Diagnostic DTC:B2278

DTC Code DTC Name
B2278 Engine Switch Circuit Malfunction

DESCRIPTION

This DTC is stored 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 between the main body ECU and engine switch is abnormal or the engine switch is defective.

  • Main body ECU

  • Engine switch

  • Harness or connector

WIRING DIAGRAM

A01ERQRE03

INSPECTION PROCEDURE

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER (START SWITCH 1, 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 Switch1 Start switch 1/ON or OFF

      ON: Engine switch on (IG)

      OFF: Engine switch off

      		 -
      Start Switch2 Start switch 2/ON or OFF

      ON: Engine switch on (IG)

      OFF: Engine switch off

      		 -
      OK
      When the engine switch is turned on (IG), ON is displayed on the intelligent tester.

    NG

    INSPECT ENGINE SWITCH Click here

    OK

  2. CHECK WHETHER DTC OUTPUT RECURS


    1. Clear the DTCs Click here.

    2. Turn the engine switch on (IG), and check whether DTC B2278 is output.

      Result
      Result Proceed to
      No DTC output A
      DTC B2278 output B

    B

    REPLACE MAIN BODY ECU (COWL SIDE JUNCTION BLOCK LH)

    A

    USE SIMULATION METHOD TO CHECK Click here

  3. INSPECT ENGINE SWITCH

    A01ERZSE06

    1. Disconnect the E18 engine switch connector.

    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
      Result
      Result Proceed to
      OK A
      NG (for 3UR-FE) B
      NG (for 1UR-FE) C

    B

    REPLACE ENGINE SWITCH Click here

    C

    REPLACE ENGINE SWITCH Click here

    A

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

    A01EPINE06

    1. Disconnect the E1 main body ECU connector.

    2. Disconnect the E18 engine switch connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E1-17 (SSW1) - E18-7 (SS1) Always Below 1 Ω
      E1-16 (SSW2) - E18-2 (SS2) Always Below 1 Ω
      E18-5 (GND) - Body ground Always Below 1 Ω
      E1-17 (SSW1) or E18-7 (SS1) - Body ground Always 10 kΩ or higher
      E1-16 (SSW2) or E18-2 (SS2) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE MAIN BODY ECU (COWL SIDE JUNCTION BLOCK LH)