U0640: Lost Communication With EVAP Fuel Vapor Temperature Sensor Circuit
What Does U0640 Mean?
U0640 is a diagnostic trouble code indicating: Lost Communication With EVAP Fuel Vapor Temperature Sensor Circuit. This code relates to the vehicle systems system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.
What To Do Next
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1
Find your vehicle above
Click your make and model for real owner reports and common causes specific to your vehicle.
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2
Check for recalls
Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.
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3
Get a professional diagnosis
A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.
Related Codes
U0635
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U0636
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U0637
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U0638
Lost Communication With Hybrid/EV Electronics Coolant Temperature Sensor A
U0639
Lost Communication With Hybrid/EV Electronics Coolant Temperature Sensor B
U0641
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U0642
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U0643
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