ABS light keeps coming on?

Sometime when I start the Tahoe and back out of the driveway the ABS light will be on. The tranny will not shift out of 1st gear while this light is on. The speedometer is at 0 also.
Any info on how this problem needs to be addressed and maybe a diagram on where the problem is.
Thanks in advance Nick

Thank you sir. Is this something that autozone can pinpoint or will their scanner just give me a general problem area.

I was reading a little bit a few minutes ago and some people are saying that the speed sensor connectors can get metal shavings in them from the brake dust and cause the sensors not to read right. Im gonna go try and bleed the brakes one day this week and im gonna take a look at the connections also. Im looking for an answer to the topic below mine about brakes being bled also. The wife says the brake pedal has too much travel. Im used to it so it doesnt bother me.

What boggles my mind is why the tranny stays in 1st gear and wont come out until the light is off. I could understand the speedo and light issue but the tranny has me wondering.

Sometime (not often at all) when I start to come to a stop at a low speed I can feel some sort of feeling in the brake pedal and the speedo will go to 0 and the tahoe will be hard to stop. This is maybe going less than 10mph. It is a weird feeling and very hard to explain what it feels like. Its almost like their may be an air pocket in the line but I dont think that is the case at all.

I went to Autozone today for the heck of it just to see what kind of codes it was showing. No shops were open on sundays. The check engine light has been on for a couple of years. The code that was read was p0430

Will it just show a speed sensor code when it acts up or will it have it in there from previos occurances from when it has happened.

Im gonna take it tomorrow and get the tranny fluid flushed out and replaced. I went fishing this morning and doing down the road about a mile from the house the ABS light came on. Speedometer went to 0, when I press the gas it is like it is in neutral. It finally slowed down enough and it was like it was in 1st gear. I could manually put it in 2nd and it would go fine. When I would try for 3rd gear nothing was there. Same way in "D". After a minute or two of dealing with it everything was fine. Fished til lunch time and loaded the boat on the trailer and went back home. No issues what so ever since this morning.
I just dont understand. Could it be a sensor on the tranny?

I went to autozone to get some stuff and talked to a guy there that has a suburban to see if he has had any issues like me. I descibed the issue and he said he thinks it would be the speed sensor on the side of the tranny or transfer case. Does anyone have a diagram or picture of where this thing is located. Is this something I could do or should I take it to a shop that has a lift.

The abs light has recently came on. I replaced both front hubs 5 months ago to fix speed sensor problems. What could be problem for light coming on now?