U0421

U0421 Ford engine fault code diagnosis, code meaning,symptoms and how to fix it.

U0421 Diagnosis

The output circuits that are powered by VBAT3 will all be inoperative. Other fault codes may be present, but troubleshoot for this first. The fuse in the main PDM powering this circuit may be open.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 U0421 Fault Code Meaning :

Ford U0421 Symptoms :

Ford U0421 Reasons :

How To Fix Ford U0421 Trouble Code ?

Which Ford cars have the code U0421?

  • U0421 Ford Aerostar
  • U0421 Ford Bronco
  • U0421 Ford C-Max
  • U0421 Ford C-Max Energi
  • U0421 Ford C-Max Hybrid
  • U0421 Ford Contour
  • U0421 Ford Crown Victoria
  • U0421 Ford EcoSport
  • U0421 Ford Econoline
  • U0421 Ford Edge
  • U0421 Ford Escape
  • U0421 Ford Escape Hybrid
  • U0421 Ford Escort
  • U0421 Ford Everest
  • U0421 Ford Excursion
  • U0421 Ford Expedition
  • U0421 Ford Explorer
  • U0421 Ford Explorer Sport Trac
  • U0421 Ford F-150
  • U0421 Ford F-250
  • U0421 Ford F-350
  • U0421 Ford Fiesta
  • U0421 Ford Flex
  • U0421 Ford Focus
  • U0421 Ford Focus Electric
  • U0421 Ford Freestar
  • U0421 Ford Freestyle
  • U0421 Ford Fusion
  • U0421 Ford Fusion Energi
  • U0421 Ford Fusion Hybrid
  • U0421 Ford Fusion Plug-In Hybrid
  • U0421 Ford GT
  • U0421 Ford Mustang
  • U0421 Ford Mustang Mach-E
  • U0421 Ford Mystique
  • U0421 Ford Probe
  • U0421 Ford Ranger
  • U0421 Ford Taurus
  • U0421 Ford Taurus X
  • U0421 Ford Tempo
  • U0421 Ford Thunderbird
  • U0421 Ford Transit
  • U0421 Ford Transit Connect
  • U0421 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.