Here is what I got.

When I got my vert. the speedo didn't work at all. I even got some vss ses codes. I have also having an issue with constant erratic transmission shifting which I believe is the tCC silenoid. The tcc silenoid is effected by three sensors. the TPS, VSS, and map I believe. But onto the speedo issue. I took my vss out of the tranny, took it to the local parts store and they ordered me in one. The issue they had is that two were available. One 22mm and one 53mm I think. They said they matched it up based on the one I had already. I installed the new one. Now my speedo works, but the speed is not correct on the gauge. IE.. When I am doing 45-50 is reads 20-24. I was thinking that I had the wrong one. I hooked the car up to a computer-based aldl program and the ecm is seeing correct pulses because the computer shows the correct speed. The gauge is off however. Why the two options at the parts store. I assume these are because of various rear end ratios! Right? I would think, however, the manual states that there is only one rear end ratio for 92s with automatic trannies.

I am a bit confused on what to do. Any ideas would be appreciated.

 

anybody have any ideas?

 

i have same problem there are two options that i have found one is acommon yet expensive part to fix which is the vss speed buffer thats what i need other option is the gears in the tranny you have one big gear on the sensor and a spiral one in the tranny. so to fix your problem id think it would be the gear. everything works but reads wrong? try differant speedo senso ratios every gear is 4 mph off. more goes up less goes down. go to a local tranny shop and get a bunch i bought a bunch for like $1 a piece other than that i have no idea. mine reads 20 mph when i start the car.

 

Thank you for the information.

Here is what my next step was. Basically the Speed sensor is ordered based on RPO code. Early in my restoration I lost my RPO sticker. In my service repair manual it list 3 RPO codes for that year. I went to the dealership and they gave me a part number (GM) for the sensor. They only had one option whereas the aftermarket stores all list 5-9 options for it; all of which are for different RPOs. I cross refed. the GM with an aftermarket part which also matched the RPO code in my factory service repair manual. So I ordered it. It was $131 verses the $63 I paid for the other one. I hope this does the trick. I have a erratic shift, lockup issue that I believe is caused by this issue. I want this resolved before I break open the transmission to replace the lockup switch. Who knows I might not need one. I have also learned about the buffer which sends a signal to cruise, gauge, and ECM. Someone deep in the forum posed that the signal might not be strong enough from the sensor to trigger the buffer. I don't know if it is the buffer or having the wrong vss. I have combed the local bone yards for a buffer but was unable to obtain one. I will start with today's replacement of the vss, then the buffer, then the lockup, then the ECM. If this doesn't work it is going to the dealership so they can tell me what the issue is. I just really want to fix it. The weather is going to get nice soon.

Thanks.

Any other suggestions or ideas are always appreciated.