2002 suburban trans problem

2002 1/2 ton 4x4 suburban, 100k miles, from stop sign, doesn't act like it's starting out in first gear, no slipping in reverse, and other gears shift perfectly. it just acts like it's starting away from a stop "stop light, etc.".......in 2nd gear? any ideas?

Does it have 3-4 and lock up?or just 2cnd. Also we have a Suburban forum in the Chev. section. To add I read your other post, ( now deleted) and you say you have 4th, so no 1st and 3rd? This should be scanned with a trans function scanner to look for trans codes and solenoid functions.