Did you have anything done with the tires just before the trip or on the trip (any flat tires)? Or did you have any brake work done?
If the rolling radius of the tires is different on any of them it can cause this concern that is why I was asking about the tires. It sounds like you lost or have a concern with a wheel speed sensor. The next step would be to get somebody to read the codes for you. An auto parts house can normally do this for free. Once you have the code then you can go from there. I hope this helps. If you have anymore questions please email us again. Thanks.