AXXESS GMOS-04 DATA INTERFACE FITS 2000-2013 SELECT GM VEHICLES

I didn't even know my 2006 Pontiac Grand Prix had a factory amplified sound system until I went to best buy to get a wire harness to install an after market head unit and they told me the harness was going to be over $200. They explained to me what kind of system these Grand Prix come with stock. Well, I am hard headed and I have never had to pay over $20 for a wire harness so I still bought the $17 harness and thought maybe I could just figure it out on my own with out having to pay more for the harness than I did for head unit. I installed the cheap harness and got everything up and running but everything sounded like junk and factory radio ended up sounding MUCH better than my after market. My speakers were hissing to the point it was embarrassing me if anyone got into my car. So then i bought an OEM output converter and that actually did help with the hissing but then i still couldnt make any equalizing adjustments from the head unit. I am sound stereo hobbiest so i have all sorts of different equipment in my garage and i am constantly switching out different amplifiers and subwoofers, etc. and even though the OEM took care of the hissing, I still could not do anything else adjustment wise because the factory amplifier is already set at the exact settings for factory speakers and the factory radio doesn't have equalizing adjustments like the aftermarket radio does. So, to shorten this up your factory speakers are already getting equalized by the factory amp, you can not send your your speakers a SECOND sound wave of the same kind of settings. So you do need a harness like this one. If you are looking for just getting rid of the hissing then Google OEM's but if you are like me and like to have control of your own settings then you NEED this wire harness. Trust me, I spent 2 months of trying anything I could possibly do to NOT buy the more expensive harness. I got this harness and now I can bump my subwoofers and adjust my factory speaker. I personally still kept my cheap harness because I plan on ripping every single factory audio wire out of this car and building my own, but this harness works for me until then. Good luck and save the struggle. Buy this harness. If you have not read by now then just know this harness does NOT come WITH the steering wheel functions but this harness does come compatible for you to use a harness for steering wheel functions and that is important to know because not all harnesses are compatible for the AW1 AND you will be stuck with a $60 steering wheel harness and still no way of being able to use it. This harness has a pigtail for the AW1 so do your self a favor and forget about how much it is going to cost for this harness and the steering wheel controls. I personally wish I could have found a way to pick and choose out of the 4..... 1. Door chimes, 2. Aftermarket head unit, 3. Onstar (really? Who still uses onstar but atlease the wiring is already ran to the mirror for when I install a dash cam) and 4. Steering wheel functions) all I wanted was my steering wheel and head unit but this harness made me happy for now and I'll just sell it on Ebay later. Good luck with your system and for what it is you are doing to your car that has a factory amp you need this harness. Thanks

I bought this for my truck where you have to buy a specialty wiring harness. My truck is fully loaded with all the bells an whistles an a alarm system. so in order to make all my stuff for them truck to work with the sounds an other things i had to buy this for my radio. where it is tied into all my sounds an the alarm. it works great an not at a bad price too.

Why this over the Pac Audio RadioPro 5 (RP5-GM11) ???? Because the RP5-GM11 may inject very noticeable hiss and static into your speakers. The GMOS has the ability to eliminate that problem by turning down the gain. There is no adjustment for this on the RP5-GM11.My vehicle: 2003 Hummer H2, bose sound system - OEM 6 disc head unit, bose speakers and subwoofer, and "luxury" version of the bose amp. The LUX amp is the digital one, and I can now advise that you should really know in advance which one you have before choosing an interface like this. Google lux vs premium bose amp. See attached photo (posted by another installer) We are not talking about whether or not your vehicle is a "luxury" class model or not.I upgraded my head unit to a Pioneer AVIC8200NEX. I installed two RP5-GM11's (first one had other defects besides hiss). Whether or not my new head unit wiring harness was even connected to the RP5-GM11 module, and no matter what audio source was selected even if fully connected, I expereinced a low level hiss coming from all speakers, not related to engine speed (NOT engine whine) and present whether the vehicle was running or I was just running power from the accessory key position. All my connections were double checked, soldered, and all grounds were fine.The hiss only went away when power was taken away from the RP5 unit. That only happened when I chose to "power off" the head unit completely. Hummer H2 - not the quietest vehicle, and I could clearly hear the hiss while driving under all conditions.Contact with PacAudio resulted in them having no solutions, other than telling me they tested their unit with "all trim levels" and this was the first they heard of this. They suggested I bypass the amp. A search of the internet, however, revealed others with the hiss issue.On to the GMOS. I also bought the steering wheel controller (ASWC-1) which was an easy install as the GMOS module already has a pigtail connector for the steering wheel controller - other than splicing in a red wire to the radio harness power lead, this part of it was plug and play - auto detected my head unit and all was good.As for wiring the GMOS, pretty straight forward and no more complex than the RP5-GM11. (24 pin GMOS harness that connects to one pulled from OEM radio has a solid orange wire - no mention in install directions on what it was for - the matching pinout on my OEM connector was empty there anyway, I capped off the orange wire, and it didn't matter in the end.If you have on-star, and whether or not you use on-star, I would still suggest connecting your aftermarket radio's "mute" wire to the GMOS harness mute wire. If not, whenever on-star turns on, whether by accidently hitting the steering wheel controller on-star button or not, it will shut off power to your radio. Then you get to watch it go through a start up from scratch process - not great if in a navigation mode.What makes the GMOS better?1) That adjustable gain screw adjustment. As with the RP5-GM11, both with and without the new head unit connected to the GMOS, with the gain turned all the way up, I heard the speaker hiss. Back down the gain just a little and the hiss was gone. Amen. As for volume; even with the gain turned down even more from where I set it, the sound was still louder than with the OEM. I lost nothing.2) On-Star volume can be controlled directly from steering wheel volume control - with RP5-GM11, you had to pick from one of a few preset levels and have to access the module to do so.3) The GMOS is firmware upgradeable via a common micro USB cable - with RP5-GM11, you have to get some proprietary cable from them.While the RP5-GM11 may not cause hiss issues for GM owners with the "premium" non-lux amps, I would encourage anyone with speaker hiss (not engine whine) to try this GMOS over the Pac Audio product.