Does TPMS adjust for 18 inch wheels? (I switched from 22 inch wheels)

[Tom Brennan]

Hi, I have a 2019 Platinum Edition Expedition. I recently changed from 22 inch wheels to 18's. I had no issues with the TPMS after the change (but I am not 100% sure what air pressure Town Fair Tire set the tires at). This weekend I went off-roading on the beach and aired down to 15psi. I then put air in my tires to 34 psi based on the inside door panel instructions for 18's. I now get a low-pressure warning on the dash and my display shows all tires at 34 psi. I have to hit OK on the wheel to get rid of the 4 wheel display but the low-pressure warning is still there.

1. Do I have to reset the TPMS? If so, will it know to adjust for 18's vs 22's?
2. The reset procedure in the manual is very confusing. It talks about inserting a key (see below) when there is no key insert on a 2019 - it is a FOB/Button system. Thought on how to do this?


2. Place the ignition in the off position and keep the key in the ignition.
3. Cycle the ignition to the on position with the engine off.

Thanks in advance.
T

 

[LokiWolf]

Hi, I have a 2019 Platinum Edition Expedition. I recently changed from 22 inch wheels to 18's. I had no issues with the TPMS after the change (but I am not 100% sure what air pressure Town Fair Tire set the tires at). This weekend I went off-roading on the beach and aired down to 15psi. I then put air in my tires to 34 psi based on the inside door panel instructions for 18's. I now get a low-pressure warning on the dash and my display shows all tires at 34 psi. I have to hit OK on the wheel to get rid of the 4 wheel display but the low-pressure warning is still there.

1. Do I have to reset the TPMS? If so, will it know to adjust for 18's vs 22's?
2. The reset procedure in the manual is very confusing. It talks about inserting a key (see below) when there is no key insert on a 2019 - it is a FOB/Button system. Thought on how to do this?


2. Place the ignition in the off position and keep the key in the ignition.
3. Cycle the ignition to the on position with the engine off.

Thanks in advance.
T

Your TPMS is doing just fine. It is good to go. The problem is the tire pressure limits set in the BCM. You need to use a Ford Service device or FORSCAN with a valid MS-Can adapter to edit the settings.

 

[Tom Brennan]

Thanks for that, couldn't figure out how to do it myself.

 

[Rob6805]

Your TPMS is doing just fine. It is good to go. The problem is the tire pressure limits set in the BCM. You need to use a Ford Service device or FORSCAN with a valid MS-Can adapter to edit the settings.

This. The OE 22" wheels/tires are probably spec'd to 39 psi (they are on my 21 MY) so that 34 psi you have your 18s set to is just low enough to trigger the warning light. Take a look at the max psi listed on the tires. I'm sure you can increase those 18's a bit to get the light to turn off.