If I install my AVIX-X930BT in my 2007 Tahoe (Bose/No Factory Nav) using the PAC OS-4 (and SWI-PS), will I still need to find and tap into the VSS wire?? Thanks!

need to? no, will it help to make your unit more accurate? yes

whats to find, the pac website says the the os-4 has a VSS output, so it should just be one more wire to connect in the harness.

from the website:

http://www.pac-audio.com/productDetails.aspx?ProductId=384&CategoryID=26

Product Features

Retains OnStar® when the factory radio is replaced

Retains Factory Bluetooth (2009-2010) model vehicles)

Retains rear seat audio controls

Retains factory XM

Retains all warning chimes (chime module included)

Retains back-up sensors/park assist

Retains back-up camera signal

Retains factory BOSE audio systems

Retains factory premium BOSE audio (Y91 digital. does not support fading)

Supports non-amplified audio systems

Steering wheel control harness (pre-wired)

Dual zone function

Chime volume adjustment (factory buttons)

Rear seat audio and video (GMRVD) required

OnStar volume adjustment

Retained accessory power output (R.A.P.)

Reverse Wire output

VSS (Vehicle Speed Sense) output

Illumination output

I thought so too, but I'm being told that since my truck did not have factory nav then there is no VSS wire coming from the factory harness to go to the OS-4...maybe I'll just strait wire it to the VSS anyway, found a pretty helpful youtube vid on it.

well there is not a actual VSS wire at the radio harness, but the whole reason that you need to use the expensive PAC harness instead of just a regular old wire harness, is because the factory radio gets all of its commands from the Can-bus which is the line of communication between all of the cars modules, this is how the radio knows when to turn on, when to shut off, which chimes to play for the car to get your attention (door ajar, check engine...)

the aftermarket radio can not receive these commands so the radio wont turn on, so the module "decodes" these signals from the bus and transfers then to something that the radio does understand. the module also can read things like when to trigger the dimmer wire (dims the screen when the headlights are on), when the P-brake is set, when the car is in reverse, and a standard VSS signal that you can hook up to the radio.

so just hook up all of the wires that you can (well except for the P-brake if you are going to bypass the unit)

If I install my AVIX-X930BT in my 2007 Tahoe (Bose/No Factory Nav) using the PAC OS-4 (and SWI-PS), will I still need to find and tap into the VSS wire?? Thanks!

Not sure the differences between your truck and mine. I used the pac os-4 and the swi-ps in my 2008 GMC Sierra which had Bose and no factory nav. But it did have a vss wire. That wire I believe with the factory radio was used to adjust the volume depending on speed. I connected everything including the bypass. Granted when I bought the radio I had it installed there. I will never do that again! They couldn't even get the bypass right nor did they hook up the illumination wire.

with a os-4, the module supplies the reverse, VSS, and Illum which it reads from the can-bus, so even if those wires where not at the factory harness, the pac mod supply's them so there should be no reason for any of them not getting hooked up correctly.

hey guys, sorry for the thread jack. are there instructions somewhere for the parking brake bypass on a 2008 GMC Sierra for a Pioneer AVIC-Z1?

hey guys, sorry for the thread jack. are there instructions somewhere for the parking brake bypass on a 2008 GMC Sierra for a Pioneer AVIC-Z1?

yes there is, but its not in the X series section of the forum, also dont post in there about it, just find it, its right out in the open stickied at the top.