Rollen48

Got a 2005 GMC Envoy 47k and just started doing this recently, speedometer jumps up to 90mph when only going 30 or 40 mph, and when I come to a complete stop it drops to only 30 mph???....any ideas on what it could be???

jamesmichael03

try unhooking you battery termnals then see when i would turn my key on on my old truck the speedometer would sett on 100 then when i got rolling about 30 or 40 it would set back right

SLOXCAB

iTrader: (7)

take it to the dealership they will replace it if your under 70k miles. damn chevy recalls

03 True Fire

iTrader: (1)

this happens to mine a few years back, i was under 45k miles, it would read 70 mph when im going under 20 for a school zone. i took my truck to the dealership and they replaced it free because they were on re-call

Rays B4U

If you Envoy isn't part of the 7year/70,000mile extended warranty program look into replacing your stepper motors. You can buy them on ebay and replace them yourself or I think there are guys that have an speedometer exchange program. I hear it's really expensive to have the dealer replace the cluster.

SILVERADO11

had the guages replaced on my 2005 silverado 3 times!! damn gauge clusters suck!

cm2677

Just replace the stepper motors. There are a newer set out on the market that are better the ones GM installed in the clusters at the factory.