P0421

P0421 Ford engine fault code diagnosis, code meaning,symptoms and how to fix it.

P0421 Diagnosis

This fault indicates that the circuit is drawing more current than it is designed to supply, and possibly there is a wiring fault shorting this circuit to ground. The fault remains active until the ignition is turned ON when the fault is no longer present.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 P0421 Fault Code Meaning :

Ford P0421 Symptoms :

Ford P0421 Reasons :

How To Fix Ford P0421 Trouble Code ?

Which Ford cars have the code P0421?

  • P0421 Ford Aerostar
  • P0421 Ford Bronco
  • P0421 Ford C-Max
  • P0421 Ford C-Max Energi
  • P0421 Ford C-Max Hybrid
  • P0421 Ford Contour
  • P0421 Ford Crown Victoria
  • P0421 Ford EcoSport
  • P0421 Ford Econoline
  • P0421 Ford Edge
  • P0421 Ford Escape
  • P0421 Ford Escape Hybrid
  • P0421 Ford Escort
  • P0421 Ford Everest
  • P0421 Ford Excursion
  • P0421 Ford Expedition
  • P0421 Ford Explorer
  • P0421 Ford Explorer Sport Trac
  • P0421 Ford F-150
  • P0421 Ford F-250
  • P0421 Ford F-350
  • P0421 Ford Fiesta
  • P0421 Ford Flex
  • P0421 Ford Focus
  • P0421 Ford Focus Electric
  • P0421 Ford Freestar
  • P0421 Ford Freestyle
  • P0421 Ford Fusion
  • P0421 Ford Fusion Energi
  • P0421 Ford Fusion Hybrid
  • P0421 Ford Fusion Plug-In Hybrid
  • P0421 Ford GT
  • P0421 Ford Mustang
  • P0421 Ford Mustang Mach-E
  • P0421 Ford Mystique
  • P0421 Ford Probe
  • P0421 Ford Ranger
  • P0421 Ford Taurus
  • P0421 Ford Taurus X
  • P0421 Ford Tempo
  • P0421 Ford Thunderbird
  • P0421 Ford Transit
  • P0421 Ford Transit Connect
  • P0421 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.