SMART 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.

Tech Tips

When the main body ECU is replaced with a new one and the cable from the negative (-) battery terminal is connected, the power source mode becomes IG-ON mode. When the battery is removed and reinstalled, the power source mode that was selected when the battery was removed is restored.

DTC No. DTC Detection Condition Trouble Area
B2278 Communication is abnormal between the main body ECU and engine switch or the engine switch is defective

  • Engine switch

  • Main body ECU

  • Wire harness or connector

WIRING DIAGRAM

A01CBVNE09

INSPECTION PROCEDURE

Tech Tips

Check the connector connection to the terminal to make sure that there is no abnormally such as a loose connection, deformations, etc.

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the intelligent tester on.

    4. Enter the following menus: Body / Main Body / Data List.

    5. Check the Data List of proper functioning of the engine switch.

      Tech Tips

      When using the intelligent tester with the engine switch off, turn on and off any of the door courtesy switches repeatedly at 1.5-second intervals or less until communication between the intelligent tester and vehicle starts.

      Main Body
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Start Switch1 Start Switch 1 / ON or OFF

      ON: Engine switch pushed

      OFF: Engine switch not pushed

      		 -
      Start Switch2 Start Switch 2 / ON or OFF

      ON: Engine switch pushed

      OFF: Engine switch not pushed

      		 -
      OK
      ON (engine switch is pushed) and OFF (engine switch is not pushed) appear on the screen.

    NG

    INSPECT ENGINE SWITCH Click here

    OK

  2. CHECK FOR DTC


    1. Clear the DTC Click here.

    2. Turn the engine switch on (IG).

    3. Check for DTCs again.

      OK
      DTC B2278 is not output.

    NG

    REPLACE MAIN BODY ECU Click here

    OK

    USE SIMULATION METHOD TO CHECK Click here

  3. INSPECT ENGINE SWITCH


    1. Remove the engine switch (for 2GR-FE: Click here, for 2AZ-FE: Click here.

      A01CCX1E68

    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
      Text in Illustration
      *1

      Component without harness connected

      (Engine Switch)

      		 - -

      Tech Tips

      This engine switch is momentary type.

      Result
      Result Proceed to
      OK A
      NG (for 2GR-FE) B
      NG (for 2AZ-FE) C

    B

    REPLACE ENGINE SWITCH (for 2GR-FE) Click here

    C

    REPLACE ENGINE SWITCH (for 2AZ-FE) Click here

    A

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


    1. Disconnect the G48 connector from the main body ECU.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G21-7 (SS1) - G48-17 (SSW1) Always Below 1 Ω
      G21-2 (SS2) - G48-16 (SSW2) Always Below 1 Ω
      G21-5 (GND) - Body ground Always Below 1 Ω
      G21-7 (SS1) - Body ground Always 10 kΩ or higher
      G21-2 (SS2) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (MAIN BODY ECU - ENGINE SWITCH)

    OK

    REPLACE MAIN BODY ECU Click here