.... When reconnected after the tire change the display on the dash came up saying manual and the system will not hold air. .....
If the sensor has moved or cycled at all while the height rod wasn't connected,
that's the message you get.

So I'd just connect it all back up; maybe check the air-bag pressure (& if it's any lower than about 10 psi or so I'd use a manual inflator add a touch of air to bring it up to saay 40 psi or so); then go for a gentle ryde. Once the sensor is reconnected and cycled a few times, there's a good chance your 'Manual' warning will disappear - it's really only telling you the computer doesn't know what's going on so manually check it out &/or add some air manually until the pressurising system has enough pressure to work out whatever it is it needs to do to bring it all back on-line properly.

It could even just be that there's not enough bag pressure in there to hold the 'Non-Return Valve closed (or is that open?! :dontknow: ) so all you need is enough air pressure in there to let the system know if it has to
Add some air, or if it should Bleed some air. :helpsmilie:
Regardless, make sure you've connected the height sensor & it's in the correct orientation, add some air to the air bag manually, then go for a ryde & see what happens. :thumbup:
Most times, that'll fix what ails your ACS when you get that 'Manual' warning....

hyea: Well, unless the compressor was running continuously beforehand, &/or one of the ACS fuses is blown; or you've pulled the air lines out of the air bag or valve; or .....
However, from what you've told us, I really can't see how the 'computer record'
OR the actual calibration of the ACS could have been lost, so I really doubt you need BUDS - it's waaayyy more likely that your ACS is just a tad confused & needs a little kick (probably just by manually adding some air!

) to work out what's going on! :gaah: Sure, it could be something more significant, but I really dounpbt it! I can't tell you
how many times I've seen that 'Manual' warning, it's been so many (I do a
LOT of miles & the standard ACS is
quite problematic...

) and
apart from the minor panic the very first time I saw it &/or the very few instances of actual physical failure in some component,
EVERY SINGLE TIME SINCE it has been resolved either by simply ignoring it & ryding on, when it fixes itself within a few hundred metres; or failing that, it's sorted just by adding a few psi of air manually!

hyea:
Good Luck! :cheers: