Code U2023, ESP light on

That particular code is a mess on Fords as it covers a lot of territory. U2023 is "Fault received from external node" and means that the powertrain control module received a bad data input from another module on the CAN network. With the ESP light on it suggests it could be a fault in that module but the only way to tell would be to use a scan tool and read the actual CAN signal to verify that it has bad data and then do a full system scan of the stability system and see if it will show what other issues are there. For that scan you need a scan tool that can show the topography of the network and if there is a data fault, similar to what this guide shows.

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

However this code can be caused by just about anything on the CAN line from a loose or corroded connection to a complete module failure. That can make it hard to track down. The ESP light being on should however have codes stored for it, you just need a higher level scan tool to read them.

It would depend entirely on what was causing the fault. The problem is that particular code isn't real specific. The ESP light being on is related to it and scanning it to find the root of the problem is what needs to be done to repair it. Beyond that it could be anything from a bad wire to a bad module. I would probably give them a chance to repair it, with the possibility of getting the money back if they cannot repair it to your satisfaction.