Speedometer stopped working!!

[Red06Z06]

This has happened to me twice now. At a car show the first time...Bloomington, parked on the Golf course, the car was sitting out in the sun for a couple hours. Went to start heading home and the damn speedometer does not work. The HUD also doesn't display a speed but the RPM's are working and everything else works fine. Just no MPH. About 20 miles down the road I see a Chevy dealer and am just about to pull in and the speedo starts working again!

So I forget about it...everything is fine. Now this weekend I was at the race track...again sitting out in the sun...I start to head home from the track and the speedo doesn't work again! Again about 20-30 miles down the road it started working again. Now I can just picture the Service tech looking at me in disbelief when I tell him what its doing. Has anyone seen this before? Heard of possible solutions? Any help would be great!

[PerforminNorman]

I hear ya. I hate the intermittent stuff.

[IT L GO]

Check and see if you have a B0516 code, which is a Speedometer signal circuit malfunction.

1. Turn the ignition key to the ON position, but do not start the car.
2. Clear any pre-set messages by pressing the RESET button.
3. Hold the OPTIONS button down, and press the FUEL button 4 times. This will get you into the CODES section of the DIC. The computer will automatically display all the codes your car has created. It will cycle through each code every 3 seconds. Any code that ends in H is a code that was registered previously but is no longer an issue.
4. Once the computer has finished going through all of it's codes, press RESET to enter Manual Configuration mode. It should start with a module and show "NO CODES" or "# CODES".
5. To optionally reset the codes once in manual mode, press and hold RESET until it displays "NO CODES".
6. Press OPTIONS button to go to the next module.
Repeat these steps until you have reset the codes in all of the modules. Note: It is not necessary to reset the codes unless you want to.

[FRISKY]

Bad connection on the green wire w/stripe that goes into the gauge cluster.

[JBP8653]

Top of diff has a wire that plugs into it. This reads the speed-o sensor on ring gear and sends info to computer. I bet it may be loose. It's hard to get to unless car is on a lift. It's also a snap fit, so maybe just needs pushing all the way in. Good luck, hope this works!

[Red06Z06]

Thanks Guys...I'll give those suggestions a try and keep you posted!