LLY Speedo buried past 120mph

[6.6Turbo]

Last weekend when it was zero degrees, the speedo stuck at 76mph. It started out from there on my next trip and did it once more. It is now buried past 120mph. I have a 05 duramax lly. I have a juice module, so I know how fast I am going, and the odometer appears to be working okay so I am not too worried, but would like to get it fixed. Anyone else have this issue or know of an easy fix?

Thanks for your help.

[mattb5150]

This is a known issue across all GM trucks, do a search for speedo or gauges. My wife's 2005 1/2 ton Suburban had the same intermittent problem. I think GM came out with an extended warranty on this til 70 or 80k miles, of course ours was already over the mileage when it occurred and its intermittent so we didn't pursue it.

[GMC Tech]

GM has a special policy on this, But its for 03 and 04. However since this has been such an issue with vehicles that are in the 05 - 06 range GM may take care of it. Ask your dealer to contact his factory rep and ask for help.

[6.6Turbo]

Battery was almost dead and tried starting, all gauges reset, speedo is working again.

[Kennedy]

For future reference, check out Florida Speedometer online. I have no experience with them, but have heard they do a good job of fixing these clusters.

It sounds like you have weak batteries. I'd suggest replacing before they take out your alternator.

[Roy W]

I'm having the same problem. The word on the street is GM will fix it under warranty if it was manufactured before 12/04 and has less than 70,000 miles. I took my '05 to the dealer and they quietly acknowledged the extended warranty on the instrument cluster.