You are using the performance key ?
You are using the performance key ?It won’t go over 40 miles an hour it like it hit the rev limiter and when you’re at 40 miles an hour and won’t go no faster it ran off into the water they had sand in it I clean the gas tank out I clean the injectors out as new spark plugs I took the heads off don’t really see anything wrong with it besides the valves leak a little bit around them
I have the same problem won’t show any codes already disconnected battery had it reset not in limp mode changed the belt, seat belt bypass is working can’t figure it outWhen mine went in to that 40 mph mode I got a "Transmission Error" scroll across the display and the "Check engine" light came on. I worked the shift lever back and forth for some time and it went away. I didnt drown or go through any deep water like you stated. The gear shift sensor must be inside the trans as I didnt see anything when I got home to do the maintenance. Try working the shift lever back and forth. Worth a try.