Anyone ever had an issue where the backcourse resets and won't let you move it? Today I was flying into KPHX and couldn't get the ILS to capture on two attempts. What I realized was happening is that I would set the backcourse (both sides) to the correct setting, but then at some point on final it would reset to 80 degrees and freeze there, making it so that I couldn't capture the VOR. Anyone know how to correct this?

I don't think you mean "backcourse," there are few if any left in the US.  Sounds like you intend to set the ILS localizer course, using the current course as published (078).  There is often a difference between the published course and the one contained in the scenery, which is years old and a few degrees different.  In this case the P3D scenery probably is 080. 

There is an option in the PMDG Simulation options that forces the course to the value used in P3D, which is something that is useful and I recommend always be enabled.  See Introduction pg 86.

Final word, you may want to browse the Introduction document on occasion at least to know what is in there.

There shouldn’t be a discrepancy though, because I keep my navaids in P3D constantly updated. I’ve also never experienced this before. The published course is 258 for runway 08. I think 080 is the course for the opposite runway. Because what happened on the second attempt is I overthrew the runway, and once I was past the runway the ILS kicked in and try to get me to do a nose dive and 180° turn

Situation update: it appears this is not a PMDG issue of any kind, it was an issue with my pro ATC add on. Even though I had it set to not mess with my autopilot, there’s some kind of bug in the program that is making it want to reset the course, and incorrectly at that. I have discontinued use of the ad on for now and that seems to be fixing the problem. Thanks!

22 hours ago, cleonpack93 said:

The published course is 258 for runway 08.

Uh? What is your source?  First of all a runway designated 08 is going to have a course or bearing of 080 degrees +/- 5 deg.  My current chart for KPHX ILS 08 indicates ILS course is 078.

It just so happens, as is the case for many airports, that ILS 08 and ILS 26 share the same frequency 111.75; however they are not the same beam but are two separate transmitters and antennas.  The way the simulator handles this is by logically selecting the beam depending on your location with respect to the runway.  There is no backcourse for either if the simulator's scenery for KPHX is correctly set up.

Many ILS finals are approached via the airport and you then fly a „back course“ with a following turn of 40(?) degrees left and then 220(?) degrees right. This might be the 258dg on the chart... 

but actually a real „backcourse“ is something completely different... where you use the localizer of the opposite runway...

1 hour ago, Ephedrin said:

Many ILS finals are approached via the airport and you then fly a „back course“ with a following turn of 40(?) degrees left and then 220(?) degrees right. This might be the 258dg on the chart... 

but actually a real „backcourse“ is something completely different... where you use the localizer of the opposite runway...

I have all of the Jepps for Phoenix and I assure you no one is flying a backcourse approach there.  Just trying to help the OP clarifying just what a localizer course is.