GTDanny

My daughters 05 Cobalt speedo. starts jumping back and forth while sitting at a stop light sometimes. Also sometimes the gas pedal stops working shortly after she takes off, I'm not sure if both are related. She told about the gas pedal thing a little awhile ago and the speedo is a new thing. I have replaced the gas pedal assembly a few months ago. The problem still continues. We also took it to the dealer way back to trouble shoot but had no luck in finding out the problem. Go figure. Would the TB have anything to do with the pedal stop working? I'm thinking it doesn't. Please help.

guitarenvy

If the dealer can make the problem happen while they are diagnosing it, there should be no reason for not diagnosing it. If you had any accel pedal or throttle body issues, these vehicle should 99% of the time set a DTC code that is required for diagnosis (not to be confused with the chk engine light being on). If on the other hand, the problem is very intermittent and the dealer cant duplicate it and there are no codes stored, then it will be difficult to figure out.

Mr.N00bLaR

iTrader: (7)

Speed sensor / harness is my guess. I pretty much had exactly what you are describing happen to me. The harness shorted is what I was told.

EDIT: Here was my thread. I did not do the work myself but they cut out the old wiring and showed me what had happened. Don't have any pics of it damaged in the car though, sorry.

GTDanny

Where is this harness located and what color is the speed sensor wire?

Thanks, Danny