My friend has a 1990 Pontiac Bonneville LE FWD 3.8L V-6 FI She lost her speedometer and trip odom all at once, Tach is working no other problems I dont have a manual to this car and dont know where exactly the VSS is located on the transmission and once located testing proceedures to confirm what I think is a bad VSS, {Parameters ect!} Can anybody tell me where its located testing instructions, or better yet a site to go to that actually has an exploded view of what I need and testing references, shes on SS and I cant afford to eat this if I get it wrong, meaning easter egg swapping, Also Ive found 3 different types of sensors for replacement, and not sure which one she needs yet! Vin# 1g2hx54c3L1 first eleven didgits. Any help would be greatly appreciated!

The VSS is located on the transaxle just below the power steering pump. Check the connector first then the resistance of the coil.

OK I found the sensor, But I dont know what the resistance value should be {I know how to use a ohm meter} how many OHMs should it be what connector tabs do I apply test probes to? Appreciate the reply but need some more parameters to go by! Do you know where an online manual is? Tthat would outline these parameters and proceedure, I just want to confirm its bad before ordering this part, I will recheck connector clean if nessecary, burnish contacts and see if it lights off. If no function after that then I must check to confirm bad!

Is a code set? Code 24 is VSS which means the ECM is not receiving from the trans.

If no code is set and no speedometer.
You have to get to the ECM connector check C2-B11 (connector 2 pin = B11) this goes to the speedometer.

Jack the front up and rotate a wheel. Check voltage at the ECM connector. it should go from 1volt to 2.5volts. If it does then the ECM is working fine and the problem is the speedometer or the wires going to it. If it doesn't work it may be the ECM.

Hint: check these pins as well: at C1 - D1, D6, D7, and at C2 - A2, they are all grounds so make sure you get 0 ohms.

If the doors have the automatic seat belts this same signal goes there too. Unplug each connector at the seat belt module (on the door) and see if the speedo comes back.

KEOTOK, Your the man, Thankyou so much for that well defined testing procedure and parameters, I e-mailed ya my mail address, and look forward to that PDF schematic. Ill get on it this weekend, and let you know how it went, I feel the love again! "SIDEWAYS OUT"