Hey guys! Just wanted to pass along some information in case it helps someone in the future. I Recently purchased a SCT X4 tuner to use with my 2014 F-150 5.0L V8. I kept getting these error codes 21301 and 11020 when trying to read the vehicle information before the actual tuning process. I could not wrap my head around why I wasn't able to get the vehicle info when the device worked on other cars that I have. After much headache and online forums I came across a Youtube video ( ) mentioning that if you have LoJack or other security systems installed on your vehicle, there could be a "piggyback" OBD2 adapter installed on your actual port . (What also tipped me off was that my "OBD2 port" on the truck fit differently from the OBD2 ports on my other vehicles. The SCT X4 tuner adapter did not fit as snug as when I connected it to the other vehicle ports). Sure enough, I remember when I purchased this truck from the dealership, they had LoJack installed on some of their vehicles. So I went to check and indeed there was an adapter cable installed onto my ACTUAL OBD2 port. so what I had to do was unplug that adapter piece and actually connect the tuner to my real OBD2 port, now it works as it should!!!


TLDR: If you get these error codes on the SCT X4 tuning device, make sure you are connecting to the actual OBD2 port and not an adapter piece installed through a security system/dealership.