The daytime running lights on my 2003 Chevy Tahoe do not turn on automatically anymore. The bulbs work, and the fuse is in tact, so what's the problem?

pushing the dome light button rapidly 6 times resets the day running lights on and off. do this run your motor turn it off then when you start it again it should be reset.

I should say the dome light button by the headlight switch on the dash, not the dome light LOL thought I would clarify that

check the computer, could be a programing problem

@gamma did you ever find the cause of your problem with the DRLs my 02 is doing the same thing....

Sorry paratrooper. I didn't see your correction below about the dome override button instead of the dome light. Whaterever happend to just "on/off" toggle switches!!

Regarding the answer given below, for my 01 Tahoe, I can turn off my DRL feature by pressing the "Dome Override" button (not the dome light button) below the headlight control switch 4 times within about 5 second. Maybe you have to press it 6 times for an '03, but mine emits a chime when it works. This button mashing only shuts off the DRL until you turn off the ignition. The next time you turn the key on, the DRL will turn on again. If you never turned your key off, you'd turn the DRL back on by again pressing the dome override 4 (or 6?) times rapidly. I assume this feature is useful when you are parked and don't want your lights glaring in someone living room window or buring the hair off of someones head while in line at a fat food restaurant. I know if you have your parking brake on the DRL won't turn on, but if that switch was defective, I'd assume you'd have a Parking Brake warning light lit on the dash.
I'm tracing a similar problem on my 01 Tahoe. My low beam headlights are on constantly and my DRL never come on at all. I just replaced the DRL bulbs because the old ones were fried, I mean they were literally overheated at the base, and they are still defective. My fuse in the box under the hood is good. I may try swapping out the DRL module in the fuse box under the hood next.
Good luck