Hello,

I have a 99 Zr2. My speedometer has been inoperative for a while now. It jumps all over the place, but shifting is fine.

The Tach, Odometer and other gauges function fine. ABS light comes and goes, but I am not sure whether this is related.

I know there are several speed sensors on our trucks, does anyone know which one controls the speedo, and how to test them? Are there speed sensors on the rear hubs?

I have replaced both front hubs since this has started, but never looked at the rear hub sensors, nor the tcase sensor. How do I test the sensors to determine whether it is a sensor/short or gauge issue?

Cheers.

 

So after some more research (Please correct me if I am wrong) it seems as though the VSS sends signal on 2 wires from my Tcase (NV236) to the PCM, which then sends the signal to my gauge cluster.

Does anyone have a wiring diagram that shows the VSS / PCM / Cluster wiring & colors?

If I am testing the VSS for AC voltage, am I just putting red / black problems on each wire, or am I going black probe to ground / red to one wire at a time?

If The ODO gets its reading from the VSS as well, it is still functioning, which would tell me it is definitely the cluster, correct?

 

Some questions;
1) does your cruise work ok?
2) does the Odometer work ok?

If yes and yes, then there's no reason to test the VSS, it's fine. My experience is the small nuts/screws which connect the circuit board (film) to the sine-cosine connectors on the gauges are the usually culprits. Just gently loosen, wipe and re-tighten them.

 

Just a bump & and update.

Cruise Control & Odometer work perfectly fine.

I Pulled the cluster apart today. The Stepper motor for both the Tach & Speedo are the same part number, so I swapped them. In this scenario the Tach still worked fine, and the speedo still exibits the same symptoms.

I believe this should rule out the VSS & the Stepper motor.

Any other suggestions?

There are no nuts or film circuit board on my cluster.

 

I have a 99 jimmy I just put a trans in. I have one wire I can't find where to plug it in at. It must run the speedo because it won't work and also won't let the trans shift. The wire runs off of the big plug that goes into the top of the trans right behind the filler tube. It is a 2 wire with a male plug and has a blue seal on it. It is about 18 inches long and would probably go up on top of the transfer case maybe. I have the two sensors on the back ot the transfer case pluge in and I think they are right, because the wires only reach so far to each. There must be another female plug on top somewhere I am missing.. Any help would be great. Thanks

 

Bellert.. you DO have circuit boards. What did the steppers plug into?


Killer.. sorry you still havent found that .. tell me, is it the same plug as for the sensors?

 

Yes the wire I am looking to plug in is just like the two on the back of the transfer case. They all have the blue seal on them. I got the picture someone sent to look at on e-bay. There is a female plug way up on top by the vent tube and I just am having a time reaching up from the bottom on a creeper and finding it. There is very little space between the floor and the top of the transfer case. I am going to keep trying to get it hooked up. I think I am on the right track, and any help will be great.
Jack C.

 

Any luck?