C0991

C0991 Ford engine fault code diagnosis, code meaning,symptoms and how to fix it.

C0991 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 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 FF.

The BHM drives the 5 cab overhead clearance and ID lamps from connector B5 pin C on circuit 46. All other marker and tail lamps are driven from BHM connector B1,K on circuit 23. This circuit connects to the CHM as an input at connector J3,P.

Ford C0991 Fault Code Meaning :

Ford C0991 Symptoms :

Ford C0991 Reasons :

How To Fix Ford C0991 Trouble Code ?

Which Ford cars have the code C0991?

  • C0991 Ford Aerostar
  • C0991 Ford Bronco
  • C0991 Ford C-Max
  • C0991 Ford C-Max Energi
  • C0991 Ford C-Max Hybrid
  • C0991 Ford Contour
  • C0991 Ford Crown Victoria
  • C0991 Ford EcoSport
  • C0991 Ford Econoline
  • C0991 Ford Edge
  • C0991 Ford Escape
  • C0991 Ford Escape Hybrid
  • C0991 Ford Escort
  • C0991 Ford Everest
  • C0991 Ford Excursion
  • C0991 Ford Expedition
  • C0991 Ford Explorer
  • C0991 Ford Explorer Sport Trac
  • C0991 Ford F-150
  • C0991 Ford F-250
  • C0991 Ford F-350
  • C0991 Ford Fiesta
  • C0991 Ford Flex
  • C0991 Ford Focus
  • C0991 Ford Focus Electric
  • C0991 Ford Freestar
  • C0991 Ford Freestyle
  • C0991 Ford Fusion
  • C0991 Ford Fusion Energi
  • C0991 Ford Fusion Hybrid
  • C0991 Ford Fusion Plug-In Hybrid
  • C0991 Ford GT
  • C0991 Ford Mustang
  • C0991 Ford Mustang Mach-E
  • C0991 Ford Mystique
  • C0991 Ford Probe
  • C0991 Ford Ranger
  • C0991 Ford Taurus
  • C0991 Ford Taurus X
  • C0991 Ford Tempo
  • C0991 Ford Thunderbird
  • C0991 Ford Transit
  • C0991 Ford Transit Connect
  • C0991 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.