GM Trailer TPMS

[Raven8906]

Hi all,

Just upgraded my tow vehicle for my Momentum 399. I went from a 2015 Denali Dually to a 2020 Denali Dually. I have a TST system with the 6 sensors and booster installed on the Momentum, and the display in the truck. The new GM trucks have a more advanced trailering app which includes a TPMS that can be seen on the info in the radio display. Now I have found the P/N for the sensors GM (84338125) but I see a note in the product details that it’s not for 5th wheels. I continued my searching and ran across the following https://gm-techlink.com/?p=11028 info about the new system.

The interesting thing that caught my eye was a comment from an Ed. where he said "Additionally, there is a maximum length the sensor can be from the rear of the truck (axles no more than 23 feet from the rear of the truck) and there should not be any open panels or metal objects between the truck and TTPM sensors." The rear axle of my 399 is ~30 feet from the rear bumper of the truck.

There is also a 102 PSI limit on the sensors, and I recall the Max tire inflation on the side of my G rated Westlakes is 110 PSI. not that I run them at the full 110 anyway. However, that took me down the path of looking into the diameter of the valve stem bore on factory '18 Momentum 399 wheels. I believe GM (84338125) sensors are .433" diameter I suspect that the higher load rated wheels on the Momentum might be the larger .625" diameter.

Phewww.... I know that was long but in short. Has anyone successfully managed to acquire any sensors that work with a 2020 GMC and a 2018 triple axel Momentum?