Since I've owned my 93 the speedometer has had the same problem. When you start driving it speedometer reads 0 for about 20 minutes, then it will start working. If you really get in it it will light SES light with code 24 which will stay lit until speedometer starts working. I got the car on a lift today and checked connection to vss and there was some bare wiring on the wires just before they went into the connector. I thought I had found the problem, but after replacing the pigtail with a new connector from Corvette Central and taking it out for a drive, same problem. After driving about 20 minutes SES light came on, then went off and speedometer started working. I will note that the car had an aftermarket radio installed when I bought it which I have replaced. Could this have anything to do with the problem? The FSM says it could be the ECM or the VSS. The D8K (10456091) vss is no longer available, but I found a place that says they can make one (found them in a previous thread). Just wanted to see what ya'll think about this problem. Thanks, John.

 

Aftermarket stereo can cause your LCD to display SYS unless you fake it out with some resistors. I have never heard of one causing speedometer problems.

 

Haven't seen the SYS displayed. Just the problem as I've described. I posted when I first bought the car that the cruise control didn't work, so I replaced the vacuum lines (to the brake pedal switch, to the hard plastic line, and the elbow going into vacuum tank). When the speedometer is working the cruise now works, but it doesn't hold a steady speed, kind of lurks up and down around set speed. Could this also be related to vss? When speedometer is working the speed will jump up and down a little, even on a flat road with constant rpm and even pedal pressure.

 

I would say your cruise control issues are certainly related to your speedometer issues. Now the root of your speedometer issues I'm not sure. Could be the sensor itself, the ECM, or a connection in between somewhere. Could be something else entirely. I'm afraid I've never had that problem so I don't know the exact fix.

 

I don't know what to think. Since the vss eventually works, shouldn't it be good. Either these things work or they don't. The ECM in the car is remanufactured so I know that it has been replaced. The fsm shows the vss signal goes to ECM, then ECM sends signal to central control module, cruise control module, speed control volume in radio control head (which has been removed by one of the po's). I think the speedometer gets its signal from central control module. I'll wait and see if anybody else that reads this thread has had similar issues before I start throwing parts at it. VSS is about $70 and the ECM is a few hundred (rebuilt). Thanks for your input.

 

Hey black, I too have had some quirks lately with the vss. In checkIng mine, I read where you can take the sender out of the transmission and check for it to have tiny metal shavings that are caked onto the magnetic end of the sender causing it to malfunction. If I was guessing, it is faulty or dirty.
Just another bit of FYI. I cross referenced the vss part number at autozone for my 95 automatic tranny vss and they list a part number as SU1090 for only 35$. Seeing as I had some eBay gift cards, I used that same part number for a search and found several vendors with that for sale listed as wheel abs sensors. It hasn't arrived to test, but I figure it's worth a shot.

 

Thanks for the tip about checking for shavings. BTW, the part you bought on eBay does not look like a transmission speed sensor. There is no gear on the back and the connector on the front is in the wrong place (at least on my 93 the connector is on the outside of the dial, not in the center). Thanks again, John.

 

Still having speedometer issue and code 24. Anyone having similar issues?

 

I got your reply today, so I thought I'd chime in once again. Im in the same boat with ya. I have almost the same issue in my 95 auto. I put in that vss sensor today that I mentioned. But I currently have the car jacked up replacing back bushings, so it hasn't been out to test it. If you have an auto tranny as well, then that part number su1090 does work and fit properly with correct hook ups. I wish I could tell ya that it cured my prob. But I've got some more time before the wheels are back on the ground. Only thing useful I can add at this point is that the part is pretty cheap if you want to throw one at it to see if it cures your prob. 35-40 bucks at the zone

Just for reference, my 95 speedo works with no issues, but I have gotten the occasional (more when cold) blinking SYS. not the ses like you see to be fighting.

My squirly quirk is I get increased rpm and when hard cornering to the right and right only. I have an on ramp the I use daily that this really comes into play. I can't find any info on this but my guess is that the car is somehow having a false vss when its got some g's. I haven't consulted fsm on this yet. I'll keep posted on your thread and maybe we can both get this resolved.

 

His 93 trans has a different setup with a gear driven VSS ;
not the induction type sensor with the reluctor wheel on the output shaft you have in yours
See
http://forums.corvetteforum.com/c4-t...aft-issue.html

 

http://tech.corvettecentral.com/2011...trouble-codes/

http://www.gearhead-efi.com/Fuel-Inj...ull=1#post6626

I have a used VSS #10456091 for $50 plus shipped.