I just finished installing a Z1 in my 2003 BMW 325i, and everything seemed to be running great, but I noticed that the speed calculated in the Z1 Dynamics Screen from the VSS wire was completely off. When I'm going around 20 KM/H it says 80km/h, if am just rolling it says I am going 20km/h, by the time I get to 80 km/h it tops out at 280KM/H. Now obviosuly this is adversly effecting my nav, as it is completely off since it seems to think I am driving a rocket. But the guage on my dashbaord is accurate of course.

I have tapped the VSS wire (Black/White) in 3 places, 2 seperate wires in the J-BOX behind my glovebox(why there was 2 of the same wire I don't know so I tried them both with the same results), and then I figured I'd try to tap behind the gauges directly and saw no difference, same result. Im pretty sure it's the right wire(read this in a couple different forums) as when I push the gas it goes up (even if too quickly) and when I let off the gas it drops back to zero when I stop (even if a little late since I have long stopped before it thinks I have). it does register when I am moving backwards and all the rest of the wiring is great.

I have read again and again that my vss wire is Black/White and I just don't understand why the speed is off by so much, with the VSS wire unhooked, my nav is STILL horribly out of sync and shows me driving off the side of the road, and just "snaps" into any road that's close to what it thinks I am driving along. Help please, I am lost and without a clue......

Was the AVIC used? If so, you may need to reset the unit so it will learn the VSS in your car.

yes it was used, I bought from one of the admin from this site acutally. Well I reset the the unit again and the learning sensors as directed from the manual, now I get the grey box telling me that this feature is not available now, but yet on the hardware screen I am getting a very accurate speed pulse ranging from 0 to about 35 and it follows the acceleration like it should, but now it doesn't want to display the readings!! I know the wire is connected, so why am I getting the "this feature is not available" as if I don't have the VSS hooked up, which I obviosuly so or I would get a speed pulse reading in the menu.... Any more ideas?

It can take up to 50 miles for the unit to initialize, then you will get all the features.

thanks for your help, I will drive around for a day or 2 and see what happens

Cheers

I have the same issue with my Z1 which was brand new. At first it says the speed sense wire it getting an irregular reading(something like that) then after 1K miles it will then say the 3D is collaborated and is getting a correct speed reading. On highway the speed is correct but on local street when I first pull out ill be going 10mph and the Z1 will say 30mph. I figure the vss wire is not connected correctly but I haven’t had time to get under there and try to fix it. The cable looks like it’s connected for me correctly and making contact to red/white at EMC (02 Highlander) but it’s not working properly. I haven’t been in a hurry to fix it as most of my driving is out on long island and the outer boroughs of NYC, but when I hit the city my nav is all out of whack and has me driving right through the middle of blocks etc...

I would check the VSS I’m sure that’s the problem we are both having.

Things are only getting worse for me, and I don't know what could be wrong. after resetting the system I have driven for over 2 days I had upwards of 400,000 pulses detected by the system and 120km driven yet the sensor is still initailizing. what more funny is the distance counter is not moving.....I can see the speed pulses go up, but the distance counter is still at 0!?? and what's worse is my nav doesn't work at all!!!! I've seen it move before, but now the arrow doesn't move at all when I drive, I even modified my location to my house, and I drove across town and the arrow didn't even rotate direction... yet I have FULL signal strenth (8 little green sat pics) and a BIG OK next to my GPS signal in configuration screen, What is going on here? I was told the system would work without the vss, but it doesn't at all, infact since I have reset it the arrow doesn't move at all anymore... is this normal? are the bars on the 3d calibration screen (distance, right turn, left turn, etc) supposed to fill up as you drive... cause they are all blank. I am really frustrated and don't understand how it tells me everything is OK and installed right, but NOTHING works with the nav part of the system at all. Any advise anyone?

Could be a broken unit? I would try a different GPS ant.

I went in and relocated my GPS antennae, it seems that it may have got pinched in some plastic, cause since I have moved it, it initialized in like 3 mins and starting clocking my location and speed etc, thanks for the tips it was the antennae.

Thanks for the help