5.4L Randomly Dies with Wrench Light and P2105

Came across a rare issue recently. This applies to F150, Superduty, or E series vans with a 5.4L 3v Triton. Engine randomly dies, wrench light comes on; vehicle will not restart until you cycle the key off and back on again. DTC's present P2105 and possible U0300. The fix is baffling. Came across a rare issue recently. This applies to F150, Superduty, or E series vans with a 5.4L 3v Triton. Engine randomly dies, wrench light comes on; vehicle will not restart until you cycle the key off and back on again. DTC's present P2105 and possible U0300.

If you follow diagnostic methods, you'll likely replace the electronic throttle body and then the PCM, but the issue will still be present. I have had experience with this before. It baffles my mind each time but I knew right where to look.

So, pop your hood, and take a look at what kind of coils you have installed. My guess is they aren't Motorcraft coils. Specifically, which coil brand is installed on cylinder number 1? I uploaded a youtube video of proof!

I did a lot of testing recently with a truck with similar issues. Customer already replaced a bunch of parts. Has all new cheap alternative, no name brand coils, new PCM, new electronic throttle body, new fuel pump driver module, new fuel pump, and so on. Someone has been using the PARTS CANNON.

I can leave all the coils, swap them around, but it results in no change. The only single thing I have to do is install a Motorcraft coil on cylinder number 1. The other time I ran into this issue was on an Expedition using AC Delco coil packs. In that particular case, we had to replace all the coils.

You can read about other Ford 5.4L Triton Common Problems in Trucks.