DTC    B2278    Engine Switch Circuit Malfunction

for Preparation Click here


DESCRIPTION

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

HINT:
When the main body ECU (instrument panel junction block) is replaced with a new one and the cable from 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.
After the main body ECU (instrument panel junction block) is replaced, perform the registration procedures for the engine immobiliser system (Click here).

DTC No.
DTC Detection Condition
Trouble Area
B2278
Communication is abnormal between the main body ECU (instrument panel junction block) and engine switch or the engine switch is defective
  1. Engine switch
  2. Main body ECU (instrument panel junction block)
  3. Wire harness or connector

WIRING DIAGRAM


B157543E05


INSPECTION PROCEDURE

1.READ VALUE USING TECHSTREAM (START SWITCH)

  1. Connect the Techstream to the DLC3.

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

    HINT:
    When using the Techstream 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 Techstream and vehicle starts.

    Main Body 
    Tester Display
    		Measurement Item/Range
    		Normal Condition
    		Diagnostic Note
    Start Switch 1
    		Start Switch 1 / ON or OFF
    		ON: Engine switch is pushed
    OFF: Engine switch is not pushed
    		-
    Start Switch 22
    		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
Go to step 2
OK

REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK) 

2.INSPECT ENGINE SWITCH


  1. Remove the engine switch (Click here).


    A109252E01

  1. Disconnect the switch connector.

  1. 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

    HINT:
    This switch is a momentary type switch.


NG
REPLACE ENGINE SWITCH (Click here)
OK


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


  1. Disconnect the E51 ECU connector.


    B162569E04

  1. Disconnect the E38 switch connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    E38-7 (SS1) - E51-10 (SSW1)
    		Always
    		Below 1 Ω
    E38-2 (SS2) - E51-9 (SSW2)
    		Always
    		Below 1 Ω
    E38-5 (GND) - Body ground
    		Always
    		Below 1 Ω
    E38-7 (SS1) or E51-10 (SSW1) - Body ground
    		Always
    		10 kΩ or higher
    E38-2 (SS2) or E51-9 (SSW2) - Body ground
    		Always
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE SWITCH - MAIN BODY ECU AND BODY GROUND)
OK

REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK)