2004 denali, navigation

I'm looking to install a Pioneer AVIC-X910BT in a 2004 Denali. Been doing mostly remote starters in the past few years and haven't done a radio in a while. I know I need a factory integration adapter to maintain door chime, OnStar and interface to the factory BOSE amp. I am also looking for something to maintain steering wheel controls if available. I've seen a few products but I am more interested to see what people have used and with what success. Also wondering if people are able to install the GPS antenna in the factory antenna location in the dash with success or if it had to be placed elsewhere. Any info on this or product suggestions would be great.

After some more reading the only two solutions I have come across are the following. Steering Wheel Control Interface: PAC SWI-PSv1 OnStar / OEM Interface: GMOS-04 Can anybody comment on either of these two units?

Wheel controls, use the PAC piece. I prefer the OS2BOSE for the harness instead, but both will work. As for the antenna, stick it up inside the dash and it will work fine. No need to make it visible...Mike M2

Tech Manager

CS Dealer Services

Thanks for the reply Mike, I have run across some info lately stating the differences between the BOSE systems and that some run high level inputs to the factory amp and some are low level inputs. And surprise, surprise, I didn't bookmark the site and can't find it again. This install hasn't taken place as it wasn't a high priority for the owner so I'm still gathering bits and pieces of info as I go. Can you shed any light on how the different system operate? I hate to install something and have the sound quality be degraded with a new NAV unit due to a silly error like bypass selection. (Especially if there are multiple "compatible" units) Thanks

Update: Looks like I will finally be getting around to installing this equipment. I looked into the OS2BOSE as was suggested and it looks like now there is a OS2BOSEv2 available, assuming this is just an updated piece, nothing new from what I could tell reading descriptions. This harness/bypass still requires a separate chime module correct? I'm still set on the steering wheel control adapter as long as a newer piece isn't available I have yet to find. Installing XM also, vehicle currently has factory XM. I read you are able to use the factory antenna just need some modification to the connector. Hoping that is pretty straight forward. How about power for the XM module? Grab it at the radio connector or splice into the factory XM module connector? For VSS wire, this should be in the stock radio harness if factory nav was an option? Anybody have the color for it? I know the GM0S-04 has VSS, parking brake and reverse available at the bypass itself but I have no problem finding these elsewhere if the PAC piece is a better item. Thanks for all the help and suggestions.

VSS is GREEN/ whitse and could be at the radio harness or get it behind the cluster. Power for XM can come from the radio harness.Mike M2

Tech Manager

CS Dealer Services

Thanks for the VSS wire info. After a lot of reading yesterday I finally found some info that stated you do not need a chime module if you have Premium Bose, only for standard Bose. And also that OnStar volume can be adjusted via factory steering wheel controls w/ Premium Bose. Any experience with the Scosche GMOS2B211B bypass? It looks identical to the PAC OS2BOSE that was suggested. Wasn't sure if they were just re-branded or if there are actual internal differences.

I first found the Axxess GMOS-04 adapter when I started looking into all of this. It seemed like a good fit, seeing how it had the extra NAV wires (VSS, Reverse, ParkBrake) and used RCA inputs like I would of expected to feed into the factory amp. I already have the necessary info for the NAV wires so that is now a moot point for me. Then I found the Scosche / PAC model unit that uses high-level inputs and it started confusing me as to which would offer better sound quality if any difference at all. I liked the PAC piece because it actually references Premium BOSE, and describes how the Fader won't work, that OnStar volume is still adjustable via steering wheel controls, Chime is retained. Seems to me like the instructions on these bypass are always lacking something in one way or another. I'm sure they both get the job done at the end of the day, just need to pick one I guess and be done with it.