My 2008 silverado surges about 200 RPM's when going down the road. If I put the tow/haul button on, it stops surging. Any ideas?

 

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The throttle body may need to be cleaned due to carbon build up. This is must a suggestion, not a diagnosis. I encourage you to have the vehicle inspected by a certified technician. They will be able to offer additional information, and repair options, after a physical inspection of the vehicle.

Does this occur all the time or intermittently? Do you receive any warning lights?

Louis
GM Customer Service