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.
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 |
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WIRING DIAGRAM
INSPECTION PROCEDURE
1.READ VALUE USING TECHSTREAM (START SWITCH) |
Connect the Techstream to the DLC3.
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.
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OK | ||
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2.INSPECT ENGINE SWITCH |
Remove the engine switch (Click here).
Disconnect the switch connector.
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.
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OK | |
3.CHECK HARNESS AND CONNECTOR (ENGINE SWITCH - MAIN BODY ECU AND BODY GROUND) |
Disconnect the E51 ECU connector.
Disconnect the E38 switch connector.
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
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OK | ||
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