2024 579 x15 100% air restrict

Air filter restriction? You might have a bunch of frost in your Air filter.

 

Nothing to do with the air brakes at all. Its an indicator for your engine air filter. As mentioned above, air filter could be plugged up with snow/ice. Could also be a sensor/wiring issue. If the air filter is clear and you're making good boost/power then its probably a sensor problem.

 

You have a winter front on?

 

I'm having a similar issue that didn't start until a few days ago. I've driven in below 30 degree temps before so I'm not sure what's going on. However, for me, it only reaches 100 when pulling up hill. Once I down shift to 11th gear pulling uphill it drops to normal and once leveled out and back in 12th gear there isn't an issue. Would you by chance have an idea what that would be?