U3940

U3940 Ford engine fault code diagnosis, code meaning,symptoms and how to fix it.

U3940 Diagnosis

The fault remains active until the ignition is turned ON when the fault is no longer present. Some BHM configurations force this circuit off until the ignition switch is cycled.The position information for the switch becomes Not Available. Remove the duplicate Smart Switch, then use ServiceLink to verify that the correct Smart Switches are configured for the vehicle.

Engine starting is disabled and other optional functions may be interrupted until the fault is corrected and the ignition switch is cycled.

Ford U3940 Fault Code Meaning :

Ford U3940 Symptoms :

Ford U3940 Reasons :

How To Fix Ford U3940 Trouble Code ?

Which Ford cars have the code U3940?

  • U3940 Ford Aerostar
  • U3940 Ford Bronco
  • U3940 Ford C-Max
  • U3940 Ford C-Max Energi
  • U3940 Ford C-Max Hybrid
  • U3940 Ford Contour
  • U3940 Ford Crown Victoria
  • U3940 Ford EcoSport
  • U3940 Ford Econoline
  • U3940 Ford Edge
  • U3940 Ford Escape
  • U3940 Ford Escape Hybrid
  • U3940 Ford Escort
  • U3940 Ford Everest
  • U3940 Ford Excursion
  • U3940 Ford Expedition
  • U3940 Ford Explorer
  • U3940 Ford Explorer Sport Trac
  • U3940 Ford F-150
  • U3940 Ford F-250
  • U3940 Ford F-350
  • U3940 Ford Fiesta
  • U3940 Ford Flex
  • U3940 Ford Focus
  • U3940 Ford Focus Electric
  • U3940 Ford Freestar
  • U3940 Ford Freestyle
  • U3940 Ford Fusion
  • U3940 Ford Fusion Energi
  • U3940 Ford Fusion Hybrid
  • U3940 Ford Fusion Plug-In Hybrid
  • U3940 Ford GT
  • U3940 Ford Mustang
  • U3940 Ford Mustang Mach-E
  • U3940 Ford Mystique
  • U3940 Ford Probe
  • U3940 Ford Ranger
  • U3940 Ford Taurus
  • U3940 Ford Taurus X
  • U3940 Ford Tempo
  • U3940 Ford Thunderbird
  • U3940 Ford Transit
  • U3940 Ford Transit Connect
  • U3940 Ford Windstar

A code is a fault code and it indicates that something has gone wrong with your car's engine.

It can be caused by many different problems, including a faulty battery, a bad fuel pump, or even a cracked exhaust manifold.

You will need to diagnose the problem before you can fix it. The best way to do this is with an OBD scanner tool.

A scan tool will tell you what needs fixing and how much it will cost in order to fix that particular issue.