For those that don't know, during the facelift refresh for 2021, JLR switched from vacuum-actuated exhaust valves to electronically actuated exhaust valves. Normally, regardless of position of the exhaust valves while driving, when the vehicle is shut off they get switched and lef open but the car reverts to the "normal" or quiet setting. So the valves are open immediately on start-up but within a couple seconds they switch closed to "normal" mode, which mimics the behavior of the vacuum-activated valves. Without vacuum pressure, the valves must remain open and can only be closed once vacuum is applied.

So an interesting thing with the electronic valves--it is simply a switch open and a switch closed circuit. They do not need constant voltage to remain closed, unlike the vacuum-actuated ones that need constant vacuum pressure to keep closed. I discovered by accident that if the valves are closed and you pull the F15 fuse, they will stay closed for good--even when the car is shut off and started again, since there is no circuit available to deliver the signal to open them. For those members that said they pulled the F15 fuse and heard no discernible difference between open or closed, this may be why. If the fuse was pulled while the valves were closed they will stay that way even with F15 pulled.

Moral of the story, make sure the valves are switched open (or the car is shut off and the valves have reverted to open) before pulling the F15 fuse or it will keep the valves shut all the time.

 

So if I visually check to see if the valves are open while the car is turned off, I should be all set if the fuse has already been pulled? And, if they are closed, I guess need to put the fuse back in and pull it while the valves are open. Update: When out to the garage with my flashlight and checked, my valves are in the open position.

 

Remember, this only applies to the electronic valves in the 2021-2024 models.

 

Understood and I need to update my profile. I sold the 2017 SVR last year and now have a 2022 R. Thanks Thinder Dump.

 

LOL, well then yes this would apply to you. If they're open when the car is off and the fuse has been pulled then you're all set.

 

I just purchased a 2017 SVR complete exhaust system for my 2022 P450. Sounds like I might have an issue with the new exhaust valve design. Electronic vs. vacuum activated.

 

I suspect you may also have an issue mounting the rear of the new exhaust system as physically it is very different to the P450 system - a pair of north/south mufflers vs a large single east/west muffler.