TPMS driving me crazy

I have a 2009 Wrangler X which I bought about 2 months ago. I bought a set of take off steel wheels and put some 235/85/16s on them and put them on the vehicle. I drove it for 3 days about 100km total but always at 80kmph or lower. On the 4th day I took it out on the highway and drove about 50km at 110kmph and then the TPMS light came on and flashed for about 1 minute and then stayed on solid. I checked the pressure at that time and it was 40psi. I lowered it to 35psi and checked the spare as well and now every time i drive it it still flashes initially and then stays on solid. I checked the built in trouble codes but it says "done" indicating there are none. I dont know if there is a bad sensor or perhaps the ones in the wheels are different from the spare and are causing interference. I will probably buy a Procal unit to recalibrate the speedo and turn off the tpms. Any other sugestions would be greatly appreciated.