U3979

U3979 Ford engine fault code diagnosis, code meaning,symptoms and how to fix it.

U3979 Diagnosis

The PTO 1 output circuit is commanded OFF, but air pressure is detected at the pressure feedback switch. Troubleshoot for PTO 2 air solenoid fault, and for air pressure switch short circuit fault.Determine if the extra switch is not required for the vehicle or if the switch has been installed but the necessary reference parameter has not been programmed into the BHM.

This circuit connects to the CHM as an input at connector J3,P. The CHM passes the signal through to power the tail lamps and marker lamps from connector C2 pin G and also from connector C1 pins D, E, and F.

Ford U3979 Fault Code Meaning :

Ford U3979 Symptoms :

Ford U3979 Reasons :

How To Fix Ford U3979 Trouble Code ?

Which Ford cars have the code U3979?

  • U3979 Ford Aerostar
  • U3979 Ford Bronco
  • U3979 Ford C-Max
  • U3979 Ford C-Max Energi
  • U3979 Ford C-Max Hybrid
  • U3979 Ford Contour
  • U3979 Ford Crown Victoria
  • U3979 Ford EcoSport
  • U3979 Ford Econoline
  • U3979 Ford Edge
  • U3979 Ford Escape
  • U3979 Ford Escape Hybrid
  • U3979 Ford Escort
  • U3979 Ford Everest
  • U3979 Ford Excursion
  • U3979 Ford Expedition
  • U3979 Ford Explorer
  • U3979 Ford Explorer Sport Trac
  • U3979 Ford F-150
  • U3979 Ford F-250
  • U3979 Ford F-350
  • U3979 Ford Fiesta
  • U3979 Ford Flex
  • U3979 Ford Focus
  • U3979 Ford Focus Electric
  • U3979 Ford Freestar
  • U3979 Ford Freestyle
  • U3979 Ford Fusion
  • U3979 Ford Fusion Energi
  • U3979 Ford Fusion Hybrid
  • U3979 Ford Fusion Plug-In Hybrid
  • U3979 Ford GT
  • U3979 Ford Mustang
  • U3979 Ford Mustang Mach-E
  • U3979 Ford Mystique
  • U3979 Ford Probe
  • U3979 Ford Ranger
  • U3979 Ford Taurus
  • U3979 Ford Taurus X
  • U3979 Ford Tempo
  • U3979 Ford Thunderbird
  • U3979 Ford Transit
  • U3979 Ford Transit Connect
  • U3979 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.