I have the cat button, the antenna, but when I hit the cat button.... nothing is there at all. I see XM radio, but no channel 1.

 

Do you have OnStar Doc, since they use the small antenna over the rear hatch for that feature too.

Check your build tag in the glove box, you're looking for U2K which indicates the presence of a factory installed XM module, you can have a head unit with a "Cat" button but no XM. Are you getting a message like "XM Feature" when you press the "Cat" button?

 

I have On-Star. And I am getting the "XM Feature" text. I'll have to truck out to the parking garage at lunch to check the build.

 

Sorry to say, but you don't have an XM equipped HHR. While all HHR's are "XM Capable" not all are equipped with it.

 

So I look for a module?

 

Give this thread a read Doc, it has the kit you'll need to replicate a factory installation.....

https://www.chevyhhr.net/forums/audio-video-17/xm-installed-17272/

Or you can get a stand alone XM receiver and use the auxiliary input on the head unit.

 

I was just reading that thread. The standalone portable would also plug into the home system and my truck (bass boat and balloon trailer hauler).... practicality leans to the portable and Velcro

Cheers
Doc