2007 Silverado LS crew cab. This happened yesterday one, and again today. Speedometer goes haywire at approx 2000 rpm. ABS light, parking light and traction control light are on. Shifts so hard from 1st to 2nd, feels like being hit from behind. Turn truck off/on, get msg to have stabilitrak serviced. After vehicle sitting for a few hours, now tranny light is on, but everything else appears to be OK. Svc msg says Stabilitrak is OFF. Any suggestions?

 

Sounds like your fusebox is going haywire. have it checked out.

As for the hard 1st to 2nd shifting, I'm hoping im wrong but some of the teeth in the transmission may have broken.
Does it shift hard from 1st to 2nd EVERY time?

 

Dropped it off at the chevy dealership. Errorcodes galore, but no real fix. Claim one of two terminal connectors may have been loose. Gave it back Fri. evening, 10 min after leaving dealer, same problems, stabilitrak service message, 'slam' shifting 1st to 2nd. Now, 150 miles later, driving fine with no issues shifting fine, no error messages.

 

well thats good, if it was broken teeth in tranny, it would happen every time.

 

Is your truck still acting right? just wondering because i have an 07 tahoe doing the same thing and two diffrent dealers cant figure it out.... what exactly did they "repair" on yours?

Thanks

 

Make sure all fuses are all the way in and seated . My Truck did that and when i checked fuse box some fuses were not seated . I pushed them in and it stopped .

 

After about a week of diagnosing,, they finally decided to test each pin/cable on the wiring from the main control box. When they pulled the master connectors off the main control box, they discovered one of the pins inside the plug was loose, thus not making a solid connection. I have to believe it had been from the mfg in this condition as there shouldn't have been any reason for someone to disconnect those plugs. After that, it ran OK,, at least no more stabilitrak issues or the other crazy behavior.

I ultimately traded the truck because of the new whining sound coming from the tranny and/or rear end. I suspect it was a result of damage caused by the hard shifting and winding of the gears in the transmission while the truck was screwed up.

I would ask them to check/test the pin connectors inside the connector plugs that connect all the wiring and sensors to the master control unit.

Good luck.