My 07 GT threw this message up this afternoon.
I had new rims and snows put on the car for three weeks ago and not sure if the tire guys knew about the sensors.
I am a little paranoid b/c my wife picked up two nails in our other car's tire last month. Is it a real code or what?? Gotta find the darn guage.
Scott

 

Weird, my electronic guage won't read the LF and RR, the tires have pressure, but stem seems to shut off really quick and not allow flow to be read. Going to see my tire guy tomorrow

 

Just tale your stang for little highway spin... I got this message after cold night here in CO ... I checked the pressure (was 30) and inflated them to 32 psi first, still had the error code after testdrive... so, instead of "air expansion during high speeds", I actually think that these sensors were frozen! and I got rid of the message after tires warmed up on highway

 

I re-tested air pressures on Sunday night and got readings on all 4 tires. The tire pressures were all ok and no more sensor fault codes came up so far this week. Weird