2003 gmc envoy with avn 5510 vss problem

Hey guys, hopefully you can help me out with a problem that I'm having. Yesterday I sold my Eclipse AVN-5510 to a friend with an '03 Envoy. We put all in no problems and went for a ride. The issue is that the HU shows the vehicle speed is double what it actually is, causing navigation errors, etc. We hooked to the Dk GREEN / WHITE wire on the instrument cluster plug as was mentioned here. Does anyone have any ideas as to why this may be?

Make sure that you connected to the GREEN / WHITE wire in cavity B9 of the plug. There are 2 GREEN / WHITE wires in the cluster plug and only one is the VSS circuit.sparky

Thanks, we'll have to check that next. Any idea what the other GREEN / WHITE wire would be? Would we get any info at all if we were on the wrong wire? Speed data seems to work, just double. At a stand still the HU info says 0mph and then goes up from there when you start moving. Also, I forgot that there was a "protection circuit" on the VSS wire from the HU. When I removed the HU from my truck I just cut that wire and didn't include this item that is attached to the wire. AVN manual says that incorrect operation may occur if it's removed. So I just went out and pull the rest of it out of my truck and will have him throw it inline with his. Hopefully that'll be the fix. Thanks again

The other wire is for the DIC. The diode on the end of the VSS wire MUST be installed. This will likely be your problem. Re-attach it to the wire someplace between your deck and the cluster.sparky

Ah, it's a diode in there. That makes perfect sense if it's an alternating voltage pulse since the diode would cut that in half. Cool, thanks.

Did you recalibrate the AVN? most of them have a have to be, not sure about yours...Mike M2

Tech Manager

CS Dealer Services

Nah, didn't have to recalibrate. Buddy put the diode in line with the VSS this afternoon and it works like a champ. Thanks sparkie for the info!