I have an ’87 T/A with a 350 & auto trans. It has about 21,000 miles on it. Every once in a while, I’ve been getting a code 24 (Vehicle speed sensor fault) from my SES light recently. Also, around the same time, my speedo needle dies. I was idling down a hill once when the car just died. Don’t know if that’s related or not. It did restart with no problem. I have access to a diagnostic book which could pinpoint whether it’s the VSS or the ECM etc., but I can’t follow the diagnostics totally since I don’t have a “tech 1” or a “signal generator tester”. I couldn’t find a local junk yard with a VSS and don’t want to spend $100 on a new one just to find out that it’s not the solution. With your experiences, is it a good chance that it is the VSS and if so, what other cars, years, and transmissions would have the same style VSS that I would need.

Thanks for your input.
Stocker87

 

Yes it is related. The VSS for 87 models is located in the speedometer itself. A bad cable or disconnected cable will trigger the SES light. If it is intermittent a common problem is the plastic drive gear in the transmission. Either or, that's why you are getting a 24.

 

87 firebirds have electronic speedometers....It does sound like a VSS to me. At least thats the most likely culprit. but be sure to check the continuity of the wires as well.

 

How exactly do you remove the VSS from an '87 T/A with a 350 motor, auto transmission, electronic speedo. The VSS is located in the tail shaft of the tranny. We unbolted the single bolt holding the "U" shaped clamp but can't get the unit out without feeling like it's going to break the plastic electrical connector. Is it supposed to unscrew?

 

It just pulls out. Theres an O-ring around it to seal it. The O-ring is probably dry and holding you up. Maybe some penetrant on the outside and then try working it around. Try twisting it as you pull. Hope you get it..