Navigation Install - Speed Detection Wire?

[logan74k]

I was perusing my install manual for a Pioneer nav unit and it STRONGLY RECOMMENDS connecting the unit to the car's Speed detection circuit. Im ashamed to say Im a bit ignorant of vehicle speed detection circuits in general but my question is: does the 451 have one and where can I tap into it? Thanks.

[tigerwong58]

I don't think you need to install that wire, the GPS will track your speed.

[buellwinkle]

I would recomend you do because a cheap portable GPS only can track your speed and direction using satelite info. The problem is what if you are driving through a tunnel, heavy tree cover, below ground roads and you lose signal, the GPS has to re-acquire the signal and you lose track of where you are. Happens to me at place like Boston where there's a lot of underground roads and no GPS signal and you miss exits. So a proper permanent mounted GPS, like a factory unit or the Pioneer should use the vehicle speed sensor together with a gyro to determine where you are during intial startup and during signal losses. I have this on my MB and it's fantastic and if I spent the change to get a Pioneer in-dash unit, I would certainly spend the time to make sure it was fully installed properly.

I don't know where this wire is but there are pro-installer audio forums where you can ask. Also, ask the service dept at your dealer, they install these all the time and mark them up.

[SunDiego]

Originally Posted by whalepirot

Ours has the AVIC-D3, professionally installed with no connection to the VSS, as far as I can determine. The unit works quite well; almost as well as the nav in the 745Li.

Same here - it's not connected to the VSS (as far as I can see too), it works perfectly fine.

[spiwrx]

I called Pioneer on this and is not needed but recommended incase you loose reception it can keep better track of position. I haven't hooked mine up and its been working fine for 5 months now.

BTW, he said you could more than likely find the VSS behind the instrument cluster by probing for a wire that increases voltage with speed.

Sounds a little dangerous even with two people. But I'm sure one of you wil eventually find it....

...If you have read your users maunal you are not supposed to use your GPS for speed calculatios anyway!

[logan74k]

Thanks to everyone for your input.... I take this all to mean that nobody really knows where the vss wire is? I often check Evilution's pages for this kind of thing but it doesnt look like he has anything up for this issue on the 451.

[Napoleon12]

if you have a d3. go into the navi menu. (remember put ebreak on) then system then i think it is the connection info. at the top there should be 3 diff boxs. the one on the bottom might read hybrid. if it does then reset that by touching the box on the left. once it get recalebrated it will change from 3d hybrid to simply. it will track a bit better bc the vss is not hooked up. i have asked on here before about where the vss wire is and got no responce. i will call my buddy at the smart dealer to see if i can get the info out of him

[rollingtones]

So far I have installed 41 GPS systems in 41 smarts and not one of them has the VSS wire hooked up. I have been installing GPS since it was invented and in the early days, yes, it mattered more but the newer units are better at finding and locking onto satellites and the VSS wire is honestly just not needed.

[buellwinkle]

Originally Posted by rollingtones

So far I have installed 41 GPS systems in 41 smarts and not one of them has the VSS wire hooked up.

That's good to know, don't use you to install my GPS system. It's like when I had A/C problems with my truck recently, took it to one dealer and they said they all do that. So I told him that if they are all wrong, does that make it right? Took it to another dealer that fixed the problem and now it's great. Moral of the story, can't find one person to do it right, find another.

I've been in plenty of situations where the VSS and gyro on my factory nav in my Benz nav saved me from getting lost, because it's working in places where the GPS has no signal. Don't care about new technology, if there's no signal, there's no signal. No bit of magic is going to make a satelite signal appear in a tunnel.

[braddman]

The VSS isn't neccesary but on the AVIC-N1 like mine, it enables hybrid learning mode. Unfortunately on the CLK55 AMG, like every benz, the speed sensor is digital, and you need a CANBUS adapter to make it work correctly.

It's not worth it. I'm not sure if the SMART has digital, but it is possible.