The Mustang Forum for Track & Racing Enthusiasts

Taking your Mustang to an open track/HPDE event for the first time? Do you race competitively? This forum is for you! Log in to remove most ads.

  • Welcome to the Ford Mustang forum built for owners of the Mustang GT350, BOSS 302, GT500, and all other S550, S197, SN95, Fox Body and older Mustangs set up for open track days, road racing, and/or autocross. Join our forum, interact with others, share your build, and help us strengthen this community!

Looking for help with Code U0401

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Went to the local dealer today to have them change the tire size in the PCM, 3 hours later they tell me they are having issues tracing down a U0401 (communication) code (which must be cleared before they can proceed with tire size update). Does anyone here have any insight as to what would cause this? They wanted me to leave the car with them for "possibly a couple of days", which is something I cannot do at this time.

As always, any and all help is greatly appreciated.


Edit: changed title for clarification.

TMO Supporting Vendors

Latest posts

Buy TMO Apparel

Buy TMO Apparel