VSS Questions

[bbotzong]

I have a 2005 Scion tC and found the VSS wire under the glove box. I hooked in the purple wire and plugged it in to my 900. But, I can't tell if its working or not. How can one tell without pulling everything apart again and volt-meter testing the wire (I understand you can measure voltage across it as the speed increases, right??). Thanks!

[crtlv]

Start up your avic and then go to settings.

from there go to nav settings

from there go to gps/time settings and it will show you at the bottom right of the screen your speed.drive the car and it should be close if not spot on to your actual speed and your good.

if it dosent register speed close to your actual speed your vss wire is incorrect

[03Aviator]

Start up your avic and then go to settings.

from there go to nav settings

from there go to gps/time settings and it will show you at the bottom right of the screen your speed.drive the car and it should be close if not spot on to your actual speed and your good.

if it dosent register speed close to your actual speed your vss wire is incorrect

 

You certain of that? The reason I question that answer is you can get a decent speed reading off nothing but the GPS. I'm not trying to challenge your answer...I would just like clarification because I believe that speed that you are talking about is taken strictly off the GPS. I just want to know if I'm wrong.

[crtlv]

i have checked that before and its pretty spot on

when it gets speed from GPS there is a decent lag between actual speed and indcated on The Avic.

When you use VSS its almost to the mile Per hour on but gps lags 5 to 10 mph behind and catches up

[bbotzong]

Thanks for the info. Will try your suggestion.

[bbotzong]

Found the GPS screen... I've always found those screens interesting to watch and this one was no different. While sitting still, I was 'moving' .03 mph. I know that is because of satellite reception and the location algorithms in the unit. I started to move and it immediately recognized the speed and seemed accurate. I think to make extra sure, I'll hide or move the GPS antenna (or hit a covered parking garage) and see if the speed is still accurate. I just wish they would have programmed in a test for the VSS.

 

But, I'm still a bit confused on the voice/sound setting. I see where you can have variable sound. I've set the low end at about 30 MPH and the high end at about 50 MPH, but I can't-for-the-life-of-me tell any difference in any audio, voice nav nor radio. Any ideas?/

[WidowMaker]

i turned the dynamic volume off... my unit started to scream at me on the highway

[dahwang]

i don't think the AVIC uses VSS unless the GPS signal is low or lost. The NAV settings screen is only displaying the speed as calculated through the GPS. When I lose signal (when using tunnels or in densely populated areas), the GPS will no longer display the data, but the map will still show my vehicle moving... (as opposed to the arrow staying stationary when you usually lose GPS signal)

 

I think the VSS gets used when the GPS loses signal. VSS and the internal gyros of the AVIC are then used to calculate position and direction. Other than those times, I don't think VSS gets used.

 

When I installed the VSS wire, the only way I could check was taking a multimeter and checking the wire while driving. I have an Altima 07, so it might be different for other vehicles.

 

Also, make sure the VSS signal is analog and not a digital signal.