Speed Pulse Positive Value when Stopped

[sthompson11]

Noticed recently that my speed pulse value in connection status is not 0 when I come to a complete stop, ex. when I come to a stop light. As a result, the nav screen shows that I am continuing to be in motion. In one case, I was at the stop light long enough for my nav screen to show that I was continuing about .5 mile past the intersection. It only corrected after I started in motion again, and still took a little time. I've also noticed that my speed under 3D Callibration Status bounces between ~10-30mph during this time.

Owned this unit for 9 months. Did the bypass 6 months ago. Upgraded unit to Z120 4 months ago. Noticed issue starting about a week ago.

I would like some insight before removing the unit or bringing it in to be looked at.

Thanks.

[sthompson11]

If no one is certain about why this may be happening, I'm also willing to hear some educated guesses. Anyone?

[RonS]

If no one is certain about why this may be happening, I'm also willing to hear some educated guesses. Anyone?

 

Uneducated guess.

A few possibilities come to mind.

1. Bad VSS signal.

2. Poor GPS reception/antenna. ie, Bad GPS signal.

3. Bad Ground connection.

 

Try temporarily disconnecting your VSS wire from wherever you have it connected. It really isn't absolutely necessary, and this should eliminate it as the source of your trouble. I'm guessing your Speed Pulse readout will be zero. If not, you may have a short in this wire. However, if this fixes the problem you can either leave it off, or try reconnecting it (to a known good source).

 

If you still are experiencing phantom movement of your location, then it must be GPS related. Check your signal strength. Check for possible frayed antenna wire. Assuming the antenna is in the same location as before the problem started, you might have to replace it. But before you do, try a different location and see if the signal improves.

 

If the above doesn't help, try temporatily grounding the AVIC chassis to a know good ground using a short wire.

 

If it isn't one of these, then it is the unit itself. Does everything else work?

 

Note: I am not an EE or installer. My advice is worth exactly what you paid for it.