My car is bleeping nuts...

Hello. I already had a question answered in this forum, about a 95 lumina sedan which had problems with an erratic speedometer and shifting. I followed advice and checked the codes, which were all relating to the VSS malfunction. I changed the VSS sensor, and the malfunction came back, and the code popped back. I took the VSS apart again, sprayed the connector with solvent cleaner and placed it back, trying to check for electrical contact. Well, the car went berserk.:eek: Now it wont shift out of first shift and the spedometer is on zero, it only reads when I let go of the gas pedal. I aslo do not get any codes out the PCM, I replaced the PCM with another I had lying around, same problem. I dont know, Im about to take it to the nuthouse,:eek7: if anyone can make sense out of this, Ill be deeply grateful.. thanks.

The VSS signal conditioner is internal to the PCM, so you've all but eliminated that possibility. You may need to check the signal from the VSS (purple and yellow wires). You might also want to be sure the transmission range switch (neutral safety switch) is functioning properly.

well, I checked for continuity from the vss wires right to the PCM plug. Its allright. this is about as far as my knowledge goes. if there is any other way to check the VSS, please, let me know.

well, I checked for continuity from the vss wires right to the PCM plug. Its allright. this is about as far as my knowledge goes. if there is any other way to check the VSS, please, let me know.

I have not had this same problem, but the VSS outputs to the PCM (Computer), so you should be able to get a reading of it's output with a Scan Tool. Hook it up, select that input, and drive the vehicle while a passenger observes the readings. Or have someone drive while you observe. It sounds as though your problem is with the VSS since it got worse when you sprayed it. I have had some aftermarket parts (non AC Delco) that worked, but not properly due to incorrect signal output.