Databus retrofit in 99 grand am?

[The Grabulator]

I have searched and found nothing, so if this is a re-post I apologize.

I have a 99 grand am, and would like to install a factory head unit from a newer Grand Am that requires the databus. (I know I know get an aftermarket blah blah) well I want to retain my steering wheel controls, plus I like the newer OEM head units. Is there any way to install a module or rig up something that would emulate the 02+ GM databus so I could install a newer head unit in my car?

[RazorDX]

Anything is possible, but you may be a pioneer since everyone just goes aftermarket.

[awfulwaffle]

they sell a special harness that allows you to retain your steering wheel controls even with an aftermarket HU

[GregFarz78]

You are looking at waaaaaay too much work just buy the harness for aftermarket head units to keep the controls, the factory head unit is nothing special anyway

[sunrunner_pei]

I don't believe it's feasible, and may not even be possible. The stereo interfaces with the BCM (for theftlock VIN comparison, power on/off), your '99 doesn't have that capability. The stereo itself would have to be extensively modded to work, not to mention the dash opening enlarged (1.5 DIN to double-DIN), and the entire wiring harness redone.

In my not-so-humble opinion, it's simply not worth it.

[The Grabulator]

I did some research and found out that 99 Grand Am's do in fact have a CAN bus. It is just not pinned in the radio harness. My only question is...does it provide the same information as the 02+ databus. I found an 03 MP3 deck for pretty cheap (my ultimate goal is Grand Prix touch screen nav). I'm going to get that MP3 deck and see if I can make it work. I will post a how-to if I get it working.

[Jibo]

To answer your latest post quite simply. No.

[RocketFast321]

Originally Posted by The Grabulator

I did some research and found out that 99 Grand Am's do in fact have a CAN bus. It is just not pinned in the radio harness. My only question is...does it provide the same information as the 02+ databus. I found an 03 MP3 deck for pretty cheap (my ultimate goal is Grand Prix touch screen nav). I'm going to get that MP3 deck and see if I can make it work. I will post a how-to if I get it working.

Unless you get the whole BCM wiring out of a 01+ GA, i don't seeing it working.

[The Grabulator]

Welp, I already bought the MP3 deck (it was cheap enough) If I get this working then I will move onto the nav deck. If it doesn't work then I didn't waste too much money.

[The Grabulator]

Ok, I checked the wiring diagrams and my 99 is missing only a few wires on the radio harness.

First is the "class 2 serial data", which my car HAS that circuit just not in the radio harness, so I can tap into one of the existing CAN bus wires.

Second it's missing the "Radio On Signal". I think this is something to do with retained accessory power

there are only two other wires my harness doesn't have and I'm fairly sure they are irrelevant to the operation of the head unit. these are amplifier control (for you monsoon fanboys out there) and gain control signal which I also assume is for the monsoon amp.


Hmmmm.....

[sunrunner_pei]

Originally Posted by The Grabulator

Ok, I checked the wiring diagrams and my 99 is missing only a few wires on the radio harness.

First is the "class 2 serial data", which my car HAS that circuit just not in the radio harness, so I can tap into one of the existing CAN bus wires.

Second it's missing the "Radio On Signal". I think this is something to do with retained accessory power

there are only two other wires my harness doesn't have and I'm fairly sure they are irrelevant to the operation of the head unit. these are amplifier control (for you monsoon fanboys out there) and gain control signal which I also assume is for the monsoon amp.


Hmmmm.....

But you're missing the most crucial element: Your 1999 BCM is not going to have the programming (or I/O) needed to interface with the new HU. The 2001+ radios are turned on/off via signal from the BCM (your BCM won't be able to do that). Plus, the 2001+ radio compares the sroted VIN with the VIN stored in the BCM. Again, not only is the radio going to need to be reprogrammed with your vehicle's VIN, but chances are your BCM lacks the programming to do this comparison check for Theftlock. And without the VIN comparison, the new HU will simply lock itself.

All in all its a lot of work for something you can easily do with aftermarket components. If you pull it off, you'll be the first we know of. But honestly, people have been attempting this since the new radios were launched in 2000 (for the 2001 model year). And in those 8 years, not one person has reported a successful swap.

[The Grabulator]

Sort of an update, someone asked how I was going to make the double din radio fit in the dash...well the original dash in the car is decimated by the sun. It's all curled up and making a valiant effort at escaping. A week ago I found a GA (01) in the junkyard with a good dash. 3 hours and many curse words later I have this;



Also my BCM has been acting up (randomly turning my gauge cluster on and off) so I grabbed this:



It is also from the 01 so if the 99 databus doesn't work the way I need hopefully this BCM will. I glanced at the diagrams for the different BCM's (99 compared to 02) and the pins seem to be the same. I will have to look more closely to verify though. Also I'm pretty certain I have to bring the car to a stealership after I put the BCM in to have it programmed.

[Blackhawk]

It's not just the dash cover, that's the easy part, you can just swap the bezel. It's the structuring underneath the dash cover, it has to be hacked and the HVAC and radio mounting points have to be moved down and fabricated.

[GregFarz78]

I don't think you'll get it working but I'll bow to you if you do. I still don't understand why GM has to complicate things so much news flash no one wants to steal factory radios just keep it simple

[nineteen88ga]

I still don't understand...why are you going through so much work for another OEM radio?

[The Grabulator]

Originally Posted by nineteen88ga

I still don't understand...why are you going through so much work for another OEM radio?

I feel the OEM radio's integrate far better than aftermarket ones. (Radio controls, door chime, dimming with headlight switch, looks better in the car). I am also not very fond of most aftermarket units. I don't like fumbling around for tiny buttons as the unit flashes obnoxious fluorescent colors that don't match the interior. The ONLY aftermarket unit I like is the AVIC D3, but is too expensive for this application. This is my daily driver and I don't feel like going all out on an audio system for it. Also (albeit well cared for) this car spends the night on the street and car break-ins are VERY prominent in my area and I don't feel like dealing with someone breaking into the car to steal some flashy POS. You guys may think this is overly complicated, but the way I see it I have to change the dash anyways. While I have the dash out I will splice the two wires I need for the newer radio and make the new radio harness. Get the radio programmed (if all goes to plan) and I will be on my way.

[Jibo]

Good luck, but I am predicting a 99% chance of it not being as simple as you think.

[RocketFast321]

I wonder how the 01 BCM will work in your 99

[car audio dave]

interesting. ill agree with everyone that you have over-simplified this, but i hope to see it work.

the HVAC and radio should fit just fine in the new dash. what you need to figure out is what are you going to do about the "monsoon" stuff. i dont know if the OEM decks run on standard amps for the case in which you dont run monsoon.

[The Grabulator]

Hai Guys

Guess what....

I have successfully installed a 01+ radio in my 99 Grand Am.

I apologize for being absent from this thread for so long, this endeavor took some time but most the work is done. And really, other than the dash swap, this wasn't really that hard. I will post a How-To once I put the last of the trim pieces on (I'm le tired and it's time for a nap, so I shall put it back together tomorrow). The radio worked for 30 seconds on FM (even did that thing all the 01+'s do where the radio stays on till you open the door). After 30 seconds it read the data bus and locked itself. Now I get to bring it to the dealership and try to coax them to change the VIN stored in the radio for theftlock..

Anyways...teaser pics until I get the How-To up;

(Before Theftlock took over)


(After it read the bus)