New problem cropped up on the instrument panel. My speedometer reads 9-mph while sitting still, even with the engine off and key out. Seems to be consistent at all speeds (reads 9-mph higher than actual). Also, fuel gauge is now erratic. Any ideas on how to fix?

Have you looked into recalls on your truck? My '02 SLE had a recall on the instrument panel. I'm not sure if it would apply to your newer truck, but it could be worth a look. A trip to the dealer may be in order, one way or the other.

My speedo gets stuck indicating 60 or 70 at times. It becomes the new "0" when I start out. Having the needle "buried" while going only 10 - 20 MPH is puzzling but not worth getting upset about. I did find that when I start the engine, some sort of mechanism makes a scratching sound as it retracts the needle 5 -10 MPH each time. It doesn't get stuck every time, either.

A friend of mine who used to work as a mechanic at a Chevy dealer said they would simply change the instrument cluster. He added that it is not an inexpensive part.

The fuel gauge could be a faulty connection or fuel sending unit. If the Envoy's sender is tank mounted like most vehicles, it too can be be an expensive repair due to the labor of accessing it. Remove and reseat all the fuses in the fuse compartments. Inspect the fuse contacts for evidence of overheating (darkening of the metal). Replace any fuse that shows this evidence and note the location so it can be rechecked later. You can probably inspect wiring from the fuel level indicator in the dash that leads to the tank - pay particular attention to ground wires that originate under any screws that are threaded into rusted steel frame / body parts. Remove the offending screw / bolt and clean rust and corrosion away from the steel surface of the vehicle and terminal of the wire. Clean the threads of the screw / bolt and hole / nut. Apply a small amount of lube & reassemble. Open suspect electrical connections and flood with liberal amounts of contact cleaner. Inspect for evidence of corrosion - clean and remove where possible. Apply silicone gel designed for this purpose (used in tail light sockets, etc.) on mating connector surfaces to help keep water and dirt out. Replace the corroded or damaged connector if you have the tools and materials to do so reliably. Otherwise, reconnect and 1) hope it works now, and / or 2) bring to a shop and and let them know what you found to help save troubleshooting costs.

Auto electrical problems are a pain - good luck!

A lot of Envoy clusters have the steppler motors fail. I'm told it is a $10.00 part to fix. There is a guy on Ebay that does speedo repairs for about $110.00. USSpeedo also repairs them, and you can get different color overlays and needles from them.

I assume that was a faulty vehicle speed sensor in your transmission. Sensors actually signals the computer to shift the transmission and also drives the speedometer.

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Hydrogen Gas Saver