I own a '99 Suburban 1500 with approx 160K miles on it.

I just finished a 600 mile round trip up to visit my dad. On my way home, I noticed that the burban seems to have some "rolling resistance", for the lack of a better term.

One thing that occured to me is that I don't feel the torque converter locking or unlocking? Shouldn't I? How would I tell if the lock-up torque converter isn't un-locking? Is there a module that connects to the trans that controls the converter lockup? Are there some basic diagnostics tests that I can do?

My Suburban is equipped with a "tow/haul" button on the end of the gear selector that is supposed to lock the converter in, along with illuminating a "tow" indicator light on the guage cluster. Currently this button doesn't seem to function .... depressing it does not activate or de-activate anything with the trans, and the light doesn't iluminate.

Admittedly, I have had a gauge cluster issue for some time. The odometer/trip odometer has been stuck in "trip" mode for awhile, and I can't switch back and forth between the two. I see this as a guage cluster problem vice a trans problem .... is this correct? Could this issue and the converter lockup issue be related? (i.e.: a faulty module controlling both??)

For reference, my tach shows approx 2200 rpm cruising at 65 on flat ground. And my seat-of-the-pants feel is that there is an internal engine resistance of some sort.

Thanks for any ideas.

Bill