I have had a PAL installed in my HHR SS for a month now.......It was installed by my selling dealer.
Today, on at least three occasions the the XM/PAL dropped out........
It kicked to FM and when I hit the band button it would only go between AM and FM and if I pressed one of the FAV buttons that were XM it would state XM not available........I found that if I pulled over and shut the car off for at least a minute it, (XM/PAL) would start working again.
Anybody have this problem or any ideas what could be wrong.

 

I had that same problem in my '06 that I had added when they first came out. I noticed that sometimes just waiting a few minutes I could cycle through and get XM or PAL.
There has been a few others that had the same problem posted late last year.