2022 GMC SIERRA 2500 AT4 BRAKE SERVICE MODE

[joeyjan]

I am trying to replace the rear brakes on my 2500 AT4. I have watched every video and read the forums on holding the brake down and the parking brake button, once it flashes on the dash, let go and then press again and it will put the truck in service mode to do the rears.

 

I cannot get the truck in the service mode doing this. the light in the dash flashes after holding, once i let go and then press the button like everyone says, it just says parking brake released. but it is not in service mode. i bought a topscan scanner to attempt to do it through the app but once again, the option isnt even in there to put the truck in service mode. when i found a service brake mode, it said "not supported". 

 

im at a loss. has anyone with a 2022 2500 AT4 experienced this? or have another method to get the truck in service mode to do the rear brakes?