Issues with 2001 gmc sierra...any ideas?
I have a 2001 GMC sierra 1500 5.3L 4x4 with the 4l60e in it. Today it started acting wierd. The speedo started bouncing. Just a little at first, but by the time I got home it was a constant bouncing back and fourth up to 20mph. It only does it in drive. If you shift down it works fine. Towards the very end of the drive it started randomly shifting and then everyonce in a while the rpm would just jump about 200. The whole time the parking brake light was randomly flashing. Not in a pattern. Just random. Where should I start looking to fix this? Wanna get it fixed before i mess something up....