Yeah, class 3 trucks don't have the tire nanny light, they just report actual pressure.
2500s are subject to the light vehicle regs, hence the low tire pressure light
Also of note, FCA updated their Witech software and now it is not an available option to lower the thresholds that kick the tire light on, on 2500s as it has been in the past.
Unless you can find a dealer that has old software, it's not happening anymore, for now anyway.
Sooooo stupid......
Not sure how it's negligent to not tell the consumer their tire pressure is off, but it's perfectly fine making people run around with 80lbs in their tires on snow covered roads or ruining perfectly good tires on dry pavement all the while lowering braking ability and lateral grip just to keep the idiot light off??
Either way, I'd air down the back tires, light or no light. Your tires and your spine will thank you!
I've read that people are getting around it by taking the tpms sensors form the wheels and putting them in a pvc pipe rigged up as a pressure vessel, air up the pipe bomb to 80 psi and toss it behind the seat or in the tool box. Haven't seen it work in person though.
