Hey everybody....
I installed the Z1 in a Charger SRT8.. I first hooked it up w/o a VSS signal, and everything seemed to work pretty well. Shortly after the install ( i.e. a week ago ) PAC Audio released their C2R-CHY unit which gives, among other things, a VSS output.. So I picked one up and re-worked my install.

Now that I've got the VSS output hooked up, when I go through a tunnel, the position indicator tracks off out into the water ( where before I hooked up the VSS Wire, it tracked along the road )... And, the Vehicle Dynamics screen reads very erratic. The S Acc, and Acc G-meters bounce around like I'm slapping the unit around or something, even though I'm just driving straight down the road at a constant speed. Even when I'm sitting still, I get G-force readings..

See this image... I'm sitting in the drive way w/ the unit. (Click the image for a full 4 Megapixel image.. BIG!)


Notice, the right meter reads -0.02g and all the rest are zero...

It's much more erratic than that on the road though... sometimes it spikes to a full G when there's no change of momentum in any direction...

Should this all settle out when the 3d Hybrid calibration is finished?? Or does it seem like an erratic VSS Signal?? And could the VSS Signal really cause all of this??

Any assistance is greatly appreciated...
LK

You know what? I would be suspect of your VSS source. One thing you can do is go to your menu that displays your connections and check how the VSS is operating. I'm betting it's not right. How is the PAC unit picking up the VSS? It has to source it from somewhere. It sounds to me like a little homework and investigation will do you wonders in solving this.

You know, I went to PAC's website and read the instructions for your unit. They weren't the best. They say the purple/white (I think that was it) needs to be hooked up to the VSS wire coming to the radio harness. Does that require you to locate the VSS wire yourself or is it part of a harness connector? It looked to me like you had to splice it in yourself. If so, are you CERTAIN you got the correct wire?

Almost all new Chysler vehicles ( and all new vehicles by the year 2007 ) are using a new computer network system called Controller Area Network ( CAN ). ( check out www.canhack.org ... I started the hacking project.. ). Many many many signals travel over this data network. Including vehicle speed.

The PAC interface converts the speed signal that's present on the CAN bus to a normal pulsed VSS signal. The display has stabilized a bit... It seems that it's required to get about 1/4 G of force before deflection will occur now. I've not been able to "rough house" w/ the car to see if the deflection is smooth after that.. but, I will tomorrow. :)

The Connections view does show a proper VSS signal. The Speed read out in the Vehicle Dynamics view is also a little erratic, but things do seem to be slowly settling out.

Thanks for the input, and I'll keep everyone posted...
LK

Sorry.. The above post is me....

LK

Good information. The newer Ford's are CAN too...so I'm sure it's something we are all going to have to live with.

You know what's amazing about CAN technology is Chrysler started playing with "twisted pair" technology in the 80's!! This was the forerunner to what we now know as CAN. Chrysler led the way with this. I remember not too many years ago when everyone HATED Chrysler architecture. It was so complicated and "clunky". Isn't it funny now how everyone is going to have to use it.