SMART ENTRY AND START SYSTEM, Diagnostic DTC:B2278

DTC Code DTC Name
B2278 Engine Switch Circuit Malfunction

DESCRIPTION

This DTC is output if 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

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

After the main body ECU is replaced, perform the registration procedure for the engine immobiliser system.

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 (Instrument panel junction block)

  • Wire harness or connector

WIRING DIAGRAM

A017CZNE03

INSPECTION PROCEDURE

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER (START SWITCH)


    1. Connect the intelligent tester to the DLC3.

    2. Check the DATA LIST for 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 tester and vehicle starts.

      Body:
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      St SW1 Start Switch 1 / ON or OFF

      ON: Engine switch is pushed

      OFF: Engine switch is not pushed

      -
      St SW2 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
    OK
  2. INSPECT ENGINE SWITCH


    1. Remove the engine switch Click here.

      A017BKJE01
    2. Disconnect the switch connector.

    3. 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 switch is a momentary type switch.


    NG
    OK
  3. CHECK HARNESS AND CONNECTOR (ENGINE SWITCH - MAIN BODY ECU AND BODY GROUND)


    1. Disconnect the D7 ECU connector.

      A017BRUE03
    2. Disconnect the D22 switch connector.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      D22-7 (SS1) - D7-17 (SSW1) Always Below 1 Ω
      D22-2 (SS2) - D7-16 (SSW2) Always Below 1 Ω
      D22-5 (GND) - Body ground Always Below 1 Ω
      D22-7 (SS1) or D7-17 (SSW1) - Body ground Always 10 kΩ or higher
      D22-2 (SS2) or D7-16 (SSW2) - Body ground Always 10 kΩ or higher

    NG
    OK