Thread: How to add factory nav to an 05-08 with HUD

I'll do so, or i ho by another dealership

Originally Posted by DCGTP

So, youre interested in putting factory nav in your GP? you like the factory compatible features with the HUD and steering wheel controls? well, this is the how to for you!
heres some things to know, the factory nav system REQUIRES and external amp. monsoon or otherwise. the factory nav was only an option for monsoon equipped models. youll need to get an antenna, a nav unit a nav dvd and a few feet of wire. you will need to have your nav unit unlocked at the dealer ship.

the Nav unit is the same model as the corvette C6, they ebay from 500 -1000 under that title...

the DVD is about 100 searched for as grand prix nav dvd

the antenna is about 30 to 50

the hardest parts of the install are getting the nav unit and getting the HUD to show directions but when its done its pretty great. so heres how,
same install process as any other radio.

remove the center console, key ring first, then the larger DIC housing and then the 3 center console pieces. once you have the radio out pop in the nav unit the connectors should just plug right in, make sure to connect all the wires; antenna, XM, and speaker outs. the antenna is the little grey square plug with only one wire. the XM set is the 12 wire connector set with the black plastic plug. the speaker outs is the larger grey plastic one. note there is still one open connection set on the back this is the voice command mic set. put your dash back together drive to your dealership and have them unlock the unit.

once the units unlocked open it up pop in your dvd and get ready to enjoy! but not yet the hardest part is yet to come. so HUD + NAV? yes please. heres where it gets fun youll be connecting the VSS to your NAV unit. where do you begin? well get yourself out that 6' or so of wire i used 20 gauge its thick but not too thick to bend into place for a pin connection on the back of the NAV.

remember that XM plug set in the back of the NAV? you're going to be connecting the VSS to that. specifics, the VSS end location on the XM plug is pin D. So you'll now need to take apart your dash again. repeat first section skipping swapping head units.

VSS end location on the XM plug is pin D.
You'll have to look on the back of that set of wires the housing is labeled A-F on one 1/2. I used plyers to bend my 20 gauge wire into shape (folded over) and tightened to fit into the pin D spot. from there i ran the wire behind the unit down the center console under the dash out the rubber door wire boot through the body pannel and out through the fender well opening next to the PCM. The VSS wire. so your pcm has 3 sockets, the VSS is on the blue J1 socket, its pin #22, the VSS is a GREEN wire. that is the second row away from the firewall, located 6 pins RIGHT of the #28 labeled on the socket. follow this green wire back a few inches and strip a small section to connect your wire from the cabin. there are 3 yes, THREE green wires on this blue J1 socket, so make sure you double check your green wire is the right green wire. once this is done just reassemble your center console, pop in some directions, calibrate your location and enjoy the airplane hostess like guided directions with HUD indications!


heres a pic of the NAV from behind the xm is the black plastic 12 pin on the right. from this view the D pin is the 4th from the right.
https://www.dropbox.com/s/alxejgg1ta...NAV%20rear.jpg

Could someone download this picture of the wiring harness and place a red dot on the appropriate pin for the VSS wire? I am struggling here to determine the correct pin location on the 12 pin radio harness.

i called around other day to some more dealerships and got different answers so called Elkins Chevrolet and they said something different too

Could someone download this picture of the wiring harness and place a red dot on the appropriate pin for the VSS wire? I am struggling here to determine the correct pin location on the 12 pin radio harness.

BUMP

I joined this forum specifically to learn all I can about this upgrade. I currently own a 2004 GTP Comp-G and I am very interested on performing this swap.

Does anyone think there will be any issues installing this in my 04?

Matthew

This harness is great for adding the Vehicle Speed Sensor (VSS)! Just cut the box off and patch reconnect the wires as pass through. Then tap your wire from your VSS to the yellow wire which is the D wire according to the attached diagram. Then it is an extension of your factory harness that you can tap.

http://www.amazon.com/gp/product/B00...ilpage_o01_s00

It's now 2024 and I want to add an OEM nav radio to my '05 GTP CompG. With the help of my 3 volume OEM shop manual, I've discovered a few things which should make this upgrade go easier. Following pertains only to '05 but maybe thru '08 as well and, with the VSS wire, not to GXPs. The VSS tap can be done more easily from the TAC module connector (Throttle Actuator Control). It's the same wire and circuit and the only dk green one here. Not so for GXPs. An issue that I've not seen discussed anywhere is the TAN amp control wire, circuit 927. Per the manual, on my car as it was delivered with no nav but instead the 6 cd changer, this tan wire is located in the smaller C2 connector F position which is just 2 over from D where we are going to plug in our VSS wire. On a US4 car (with nav) this tan wire is over in the C1 connector which is currently occupied on my car by a gray w/black "amplifier present signal" wire, circuit 2334 I suspect I will have to move the tan here and then just tape off the gray one since the manual does not show another place for it. Phew! I don't even know yet what to do about the two pink wires for voice on the nav but most likely won't exist currently. A more troubling issue for me is that only the '08 nav owner's manual gives instructions for steering wheel controls. So if any of you out there have an OEM nav in an '05 and the steering wheel controls function please reply back. I purchased from ebay an '05 Pontiac original oem nav for myself for Christmas - with all the connectors and cut wires but won't get at this until it warms up! Trying to get list of all Denso navs with features.