U3904

U3904 Ford engine fault code diagnosis, code meaning,symptoms and how to fix it.

U3904 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 BHM is detecting more than one smart switch with the same ID number present on the vehicle. The outputs controlled by the switch and the indicator in the switch are commanded OFF.

The disconnected pipe malfunction is detected when the ventilator tube from the valve cover to the separator device is disconnected resulting in a pressure below the lower limit.Both of these malfunctions will result in a DTC being set.

Ford U3904 Fault Code Meaning :

Ford U3904 Symptoms :

Ford U3904 Reasons :

How To Fix Ford U3904 Trouble Code ?

Which Ford cars have the code U3904?

  • U3904 Ford Aerostar
  • U3904 Ford Bronco
  • U3904 Ford C-Max
  • U3904 Ford C-Max Energi
  • U3904 Ford C-Max Hybrid
  • U3904 Ford Contour
  • U3904 Ford Crown Victoria
  • U3904 Ford EcoSport
  • U3904 Ford Econoline
  • U3904 Ford Edge
  • U3904 Ford Escape
  • U3904 Ford Escape Hybrid
  • U3904 Ford Escort
  • U3904 Ford Everest
  • U3904 Ford Excursion
  • U3904 Ford Expedition
  • U3904 Ford Explorer
  • U3904 Ford Explorer Sport Trac
  • U3904 Ford F-150
  • U3904 Ford F-250
  • U3904 Ford F-350
  • U3904 Ford Fiesta
  • U3904 Ford Flex
  • U3904 Ford Focus
  • U3904 Ford Focus Electric
  • U3904 Ford Freestar
  • U3904 Ford Freestyle
  • U3904 Ford Fusion
  • U3904 Ford Fusion Energi
  • U3904 Ford Fusion Hybrid
  • U3904 Ford Fusion Plug-In Hybrid
  • U3904 Ford GT
  • U3904 Ford Mustang
  • U3904 Ford Mustang Mach-E
  • U3904 Ford Mystique
  • U3904 Ford Probe
  • U3904 Ford Ranger
  • U3904 Ford Taurus
  • U3904 Ford Taurus X
  • U3904 Ford Tempo
  • U3904 Ford Thunderbird
  • U3904 Ford Transit
  • U3904 Ford Transit Connect
  • U3904 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.