Swinging speedo

Zaairman · May 22, 2012

My speedometer has started this neat trick where it swings 5-10 MPH down at times. Not always, just randomly. Cleaned the VSS and that seemed to help some on my short drive to work, but don't know for sure yet. Only seems to do it on the highway while traveling at a constant speed. Anybody ever had a simliar problem? Was it the VSS or gauge cluster?

907DAVE · May 24, 2012

Most likely its the cluster, but you need to verify the input to your cluster is correct before blowing money away. Depending on your ABS system, this could be a function of the ABS module or PCM.

Any other symptoms such as a flashing O/D light or ABS light?

Zaairman · May 24, 2012

It's a non ABS truck. No flashing lights.

Zaairman · Jun 25, 2012

Gonna bump this one back up... It was "OK" for a bit, by that I mean it wasn't swinging 10 MPH at a time like it was before. Then, drove the truck to work today, and it was bouncing a lot. Set the cruise cause there was a cop behind me, and then the cruise was dancing with the speedo.

So, I need to confirm if the cruise gets its input from the speedometer, or from the PCM? If its the PCM, I think my VSS is bad...