new tires. low pressure light wont shut off...help.

[OC Stroker]

So I just put some 35" toyo open country mt's on my stock fx4 wheels. Look great ride awesome but I can't get the tire sensor light to shut off. Started out at 40 psi then went to 55 psi and now at 50 psi. Seems that's the sweet spot. Do I need to reset the computer or sonmething? Driven well over 20 miles and it won't shut off.

[forddieseldoctor]

what does the door say for pressure? Start with putting the pressure at what the door sticker says. You may have to get it re-pinged, or possibly a damaged sensor due to improper mounting. Ford makes a tool for pinging the tires that's very cheap. It's for the E-series, (talk to your local dealer parts department) but it works on almost all band mounted sensors. It will save you a bunch of money in the long run. I found one on ebay FORD TPMS TIRE PRESSURE SYSTEM RESET TOOL 8C2T-1A203-AB : eBay Motors (item 220602182654 end time May-15-10 04:34:54 PDT)

[cj performance]

theres a rest tool. it just doesnt go off by itself

[forddieseldoctor]

If the light is on from a low tire the light will go off after the tire pressure is fixed. however if they need to be retrained then you have to see a repair shop that has a tool to retrain the sensors.

[cj performance]

or find someone with a 08+ f350 as the tool came with the f350s..

[smotrs]

If your talking about the bands that go inside the wheel, all they do is monitor the current pressure and report to the computer. The computer is set to monitor for a given pressure range (see driver side door sticker). If the tire pressure differs significantly from what the sticker says, the computer flags the warning. If you bring the tires back within range, the warning will eventually disappear. Using the reset tool will do it quicker but not change the default in the computer.

The warning doesn't happen instantly, it takes some time. I have my tires set for 50PSI even though the computer expects 65. When I went camping for a week in the mountains, I noticed the next morning that the warning was off. The entire time I was camping the warning stayed off, but on the trip home when I got back down to my normal altitude, the warning came back on.