C3990

C3990 Ford engine fault code diagnosis, code meaning,symptoms and how to fix it.

C3990 Diagnosis

The axle lift 2 output circuit is commanded OFF, but air pressure is detected at the pressure feedback switch. Troubleshoot for axle lift 2 air solenoid fault, and for air pressure switch short circuit fault.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.

A comparison of pressures from all sensors is made. The smallest difference between the three is determined and a reference pressure is calculated. The Barometric pressure sensor value is compared to the reference value and if the difference is above the threshold a DTC is reported.

Ford C3990 Fault Code Meaning :

Ford C3990 Symptoms :

Ford C3990 Reasons :

How To Fix Ford C3990 Trouble Code ?

Which Ford cars have the code C3990?

  • C3990 Ford Aerostar
  • C3990 Ford Bronco
  • C3990 Ford C-Max
  • C3990 Ford C-Max Energi
  • C3990 Ford C-Max Hybrid
  • C3990 Ford Contour
  • C3990 Ford Crown Victoria
  • C3990 Ford EcoSport
  • C3990 Ford Econoline
  • C3990 Ford Edge
  • C3990 Ford Escape
  • C3990 Ford Escape Hybrid
  • C3990 Ford Escort
  • C3990 Ford Everest
  • C3990 Ford Excursion
  • C3990 Ford Expedition
  • C3990 Ford Explorer
  • C3990 Ford Explorer Sport Trac
  • C3990 Ford F-150
  • C3990 Ford F-250
  • C3990 Ford F-350
  • C3990 Ford Fiesta
  • C3990 Ford Flex
  • C3990 Ford Focus
  • C3990 Ford Focus Electric
  • C3990 Ford Freestar
  • C3990 Ford Freestyle
  • C3990 Ford Fusion
  • C3990 Ford Fusion Energi
  • C3990 Ford Fusion Hybrid
  • C3990 Ford Fusion Plug-In Hybrid
  • C3990 Ford GT
  • C3990 Ford Mustang
  • C3990 Ford Mustang Mach-E
  • C3990 Ford Mystique
  • C3990 Ford Probe
  • C3990 Ford Ranger
  • C3990 Ford Taurus
  • C3990 Ford Taurus X
  • C3990 Ford Tempo
  • C3990 Ford Thunderbird
  • C3990 Ford Transit
  • C3990 Ford Transit Connect
  • C3990 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.