Vss senser

I'll try to explain how a bad VSS sensor can affect your '96 Astro. (note spelling in previous sentence)

The ECM (Electronic Control Module - or Brain) of your '96 Astro uses the signal from the VSS, along with other inputs from various sensors (TPS, Baro, etc) to determine which range to put the transmission into. If the ECM sees no signal, or an obviously out of range signal, from your VSS, it's not going to know which range the transmission needs to be in, and won't shift it out of first range. This will result in excessively high engine RPM for any speed over 5 MPH, and very poor fuel mileage if you try to drive it. :-)

HTH

Jeremy

ps - try spell check next time, and remember 'effect' (while spelled correctly) is the reaction from a 'cause'.... :-)

So could a bad vss affect only overdrive gears and not first and second~~my transmisson will not engage thrid or fourth gear while in drive....Thanks for spelling lesson~~lol

no

A bad vss sensor will not allow you to get out of 1st gear, just like Jeremy explained. It doesn't affect any gear directly.

--

---------------------------------------------------------------- Ed Murray Certified Locksmith My Enthusiast's Website:

Not like you to not explain what could affect the tranny in that manor.

~KJ~

generally when a 700R4 or 4L60E loses 3rd and 4th, it's the '3-4 clutch pack' that's gone

does it 'try' to shift to 3rd and act like it's in neutral, or does it not attempt the upshift ?

Doesn't the VSS provide a signal (directly or indirectly, I'm sure it goes through the ECM) to the speedometer? I would think the speedo would read 0 MPH with a bad VSS..

I suspect you've lost the 3-4 clutch pack in your transmission. Check your trans fluid.. is it low? What color is it?

Orange/brown color is bad, as is a burnt or garlic smell.

I overheated the 700R4 in my '90 C1500 and lost 3-4. The fluid was brownish orange and smelled like garlic.

I've since installed a 'stage 2' from Bowtie Overdrives. Temperature is never above 160 (recommended operating temp) now that I've installed a cooler and watch the trans temp gauge fanatically.

-Steve

Steve my fluid was orange and the bottom of pan was black---so this 3~4 pack...what kind of cost am I looking at....Does a tranny shop have to do the job? Thanks