camarobird92

So I was told on my transmission issues to check the TPS and the VSS. My TPS is fine, but in the Chiltons book it says to check for a reference signal on the VSS by probing the 2 wires with a multimeter. It should read 5 volts. Problem is, I'm only getting 1 volt for a reference signal to the VSS. Is this a problem? My speedo is functioning correctly.

Anybody know another way to test the VSS?

Injuneer

I think the voltage varies from 0-5V as the tailshaft turns, generating 40 pulses per output shaft rotation. Since the voltage is varying over that range, when you read it with a DC volt meter, its not going to read 5V. Its going to read less.

Since the VSS only feeds the PCM, if the PCM is transferring the vehicle speed correctly to the speedometer, it would seem the PCM is getting the correct signal from the VSS and knows the vehicle speed.

camarobird92

But the Chilton's book said that ther was supposed to be a "reference signal" of 5 volts coming from the PCM. You check the wires going to the VSS with the VSS unplugged.

Injuneer

If your speedo is working, your VSS is working. How would the PCM know the vehicle speed, if it wasn't getting the signal from the VSS? Sometimes, Chiltons is not all that accurate. They transferred a lot of data from the 3rd Gen, and the VSS circuit changed in 1994.

Check Shoebox's 95 pinout data. VSS is pins A31, A32:

http://shbox.com/1/1995_pcm_conn_a.jpg

Notes are on page 1:

http://shbox.com/1/1995_pcm_conn.jpg

Those diagrams are out of the factory manual.