I recently installed the GROM BT-3 (XM firmware) in my 04 TL. I'm currently going back and forth with GROM tech support and am on my like 3rd or so firmware. It has gotten better, but it is still cutting out and there are times when I have to use pause/play on my phone to get it to reconnect.

I have a question about whether I installed it correctly. When I plugged in the GROM into the back of the radio, I DID NOT plug in the original plug that was in the radio back into the GROM supplied Y harness. My rationale was that I was disabling XM by no plugging it in. However, in searching the forum, I have seen others talk about disabling it by unplugging the XM module in the trunk. Does it matter which of these connectors are unplugged, or is it the same??

 

i had the same issue i kept hearing xm preview so i unplugged the plug from the xm unit in the trunk, it was pretty easy. but quick question if you didn't plug the orginal radio plug back in to the grom y harness how is the radio working?

 

The connector was one of several, so I was assuming that that one connector was the xm connector for the xm module and I was merely replacing the xm modules function with grom?

 

You've probably figured this out by now but just in case...
The GROM wire harness plugs into the XM interface on the back of your stereo. The XM cable plugs into the GROM harness. Using firmware 29 for 3g tl you should be able to play whatever Android or USB you have attached to the USB GROM port and have the tracks displayed on the stereo and temp display.