ENTRY AND START SYSTEM (for Start Function), 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 power source control ECU and the engine switch; or 2) either of the switches inside the engine switch is malfunctioning.

Tech Tips

When the power source control ECU is replaced with a new one and the negative (-) battery terminal is connected, the power source mode becomes the 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 power source control ECU and engine switch or the engine switch is defective

  • Engine switch

  • Power source control ECU

  • Wire harness or connector

WIRING DIAGRAM

A01603OE02

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. Check the Data List of proper functioning of the start switch.

      Tech Tips

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

      Power Source Control
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Start Switch1 Start Switch 1 / ON or OFF

      ON: Engine switch is pushed

      OFF: Engine switch is not pushed

      		 -
      Start Switch2 Start Switch 2 / ON or OFF

      ON: Engine switch is pushed

      OFF: Engine switch is 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 DTC.

      OK
      DTC B2278 is not output.

    NG

    REPLACE POWER SOURCE CONTROL ECU

    OK

    USE SIMULATION METHOD TO CHECK Click here

  3. INSPECT ENGINE SWITCH


    1. Remove the engine switch Click here.

      A015Z34E40

    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

      Tech Tips

      This engine switch is momentary type switch.


    NG

    REPLACE ENGINE SWITCH Click here

    OK

  4. CHECK HARNESS AND CONNECTOR (POWER SOURCE CONTROL ECU - ENGINE SWITCH AND BODY GROUND)


    1. A0162GUE13

      Disconnect the J55 connector from the power source control ECU.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      J31-7 (SS1) - J55-14 (SSW1) Always Below 1 Ω
      J31-2 (SS2) - J55-37 (SSW2) Always Below 1 Ω
      J31-5 (GND) - Body ground Always Below 1 Ω
      J31-7 (SS1) or J55-14 (SSW1) - Body ground Always 10 kΩ or higher
      J31-2 (SS2) or J55-37 (SSW2) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CONTROL ECU - ENGINE SWITCH)

    OK

    REPLACE POWER SOURCE CONTROL ECU