Ive got this UO401 code twice now and am wondering what this could be my sct x4 says its invalid Data Received from ECM/PCM A. Hopefully my ECM/PCM isnt going bad. any help is appreciated
Any recent work on the truck such as cab removal etc? i would check the plug connections on the drivers fender as well as the three on the pcm. make sure they are seated fully, not corroded and apply dielectric grease.