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I just have a general question. The car's speedometor will shake and drop to zero for a few minutes/miles.. and then comes back. I've figured out that its not a cable, as some people where mentioning not to change the cable until its broke... and a sensor instead. I'm driving 10hrs next week to visit for thanksgiving, and am continually told its fine to drive on it until it doesn't work. Is that true? Nothing else is affected by the "vss" sensor having whatever problem it has (That's it, right?) Driving, having to gauge myself at 70+mph for most of that trip, sounds slightly challenging enough (ive only been driving 7mos, have a 3yr old and am 16wks preg and haven't driven more than maybe a half hour on my own.... so)...i just want to know that otherwise, the car will make it, therefore us making it.. And that its not Completely stupid of me to travel like that......

 
Rep Power: 518

The VSS signal is shared by the gauges, the PCM, and the cruise control.

If there is no codes set in the PCM (P0500, P0501, P0502) then the VSS itself is ok and its wiring to the PCM is ok. A scantool connected into the datalink connector can show what the PCM sees as the vehicle speed (quick tests if you have the equipment.)

There could be wiring issues or gauge issues. See if the cruise keeps working while the speedometer drops, and maybe try banging your fist on top of the dash over the gauges. Depending on if anything else is affected, that could lead to some conclusion about where a wiring problem may lie, or if it should be a problem inside the gauge cluster.


Make notes of where the RPM gauge is at various highway MPH speeds and use that for backup in case the speedo quits on the road.

If you had a scanner that showed data, you could just leave that plugged in on the road too.