is the gps calculated from an antenna somewhere in the car or off of the tpms sensors? mine used to be dead accurate, but since I installed the snow wheels Thursday (they have their own new oem sensors), it is consistently off. I even reprogrammed the pcm to the correct rpm for the specific tire. I did not, however, retrain the new tpms sensors, though the tire light is not illuminated on the dash.

I have not experienced any change in the accuracy of the GPS in my Flex with my 18" snows on vs the stock 20".

My TPMS is not trained for my snows.

I believe GPS system in the car just uses GPS signal & antenna in car to know your location.


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FYI, from a ford tech:

Out in the open, with a clear view of the sky in all directions, disconnect the 12 volt battery for 5 minutes.

Reconnect the 12 volt battery

Turn the vehicle on and let the engine run for about 5 minutes in idle

Put an address in your navigation about a mile from your location and drive there

When you arrive at your location, put the address in the navigation to go back where you came from

Your system will now be recalibrated. The "interpolation" data that was stored in the memory of your navigation was for the 20" tires. Ric   

That's interesting as mine has never been right. I rarely use it but when I do, I seem to go offroading a lot, lol.

I've wondered if it's because my car is basically underground in the garage when it initiates.

Thanks for the tip!

Quote from: cseverens on January 18, 2016, 02:37:46 PM
FYI, from a ford tech:

Out in the open, with a clear view of the sky in all directions, disconnect the 12 volt battery for 5 minutes.

Reconnect the 12 volt battery

Turn the vehicle on and let the engine run for about 5 minutes in idle

Put an address in your navigation about a mile from your location and drive there

When you arrive at your location, put the address in the navigation to go back where you came from

Your system will now be recalibrated. The "interpolation" data that was stored in the memory of your navigation was for the 20" tires. Ric   

There is no way that is anywhere close to the explanation of the problem......that ford tech is most likely the guy is only allowed to change oil on Saturdays...his explanation is just wrong on so many levels.....let it idle for 5 minutes lol?..why..the gps is not talking to the tpms lol god

Looks like this can happen when the global position satellite module is bad.

My gps has always been off...need to go to the dealer sometime