ABS & Brake light & warnings

I'm looking for any feedback anyone might have on my situation with my ABS system. I already know the best place to start is with the ABS scanner to get the code(s) for my situation. I have the factory service manual 5-volume set so I am ready to troubleshoot / repair the problem but can't find out what the ABS code(s) are.

Symptoms:
When I first turn my truck on, the ABS and Brake lights come on and stay on (but they do shut off when the truck is turned off). Additionally, an annoying loud chiming noise comes on for about 30 seconds and a message is displayed in the odometer display -- "Service brake system." The message can be cleared from the odometer display by pushing on the odometer button. I have confirmed (thru hard stopping) that the ABS brakes no longer work.

Recent work:
1) Replaced tie-rods (but the above symptoms were happening before this)
2) Pulled front wheels off and checked bearings (ok), brakes (ok), and ABS sensor cable (ok).
3) Greased ball joints and tie rods
4) Front end alignment

Next steps:
1) Trying to figure out how I can find out the ABS code(s) without paying megabucks to my dealer. I haven't found any reasonably priced after market ABS scanners and the OBD-II scanners (under $500) don't do ABS system diagnosing. I know that some of the national auto shops (i.e. AutoZone) will do the OBD-II scan for free so I was going to check with some of them to see if they offer a free ABS scan.

2) Today, I plan on taking a look at the ABS sensors to see if any grease got on them or if they are damaged. Someone told me to lightly sand them as they are sensitive to grease, etc. Has anyone else tried this? If this is the issue and the sanding works, will the ABS light recycle itself and shut off or does it need to be cancelled by an ABS scanner?

Any other thoughts?

Pulled the front brakes apart and we found that the rotor had alot of rust on the part that the pad comes in contact with. There was just an inch wide ring in the center of the rotor where the center of the pad came in contact with the rotor. Cleaned the ABS sensor, replaced rotor and brakes, and lubricated other parts but the lights are still on.

I don't believe Auto Zone can pull ABS codes. At least mine can't.

Needs to be scanned on an abs function scanner for codes and comparative wheel speed sensor inputs, AZ cannot do this.

Monkey-girl...contact these people...
http://modulemaster.com/gmabsrepair.html they will take good care of you...the dealer here said I needed an ABS pump and EBCM that totaled about $1800. I bought a rebuilt pump and sent in my EBCM to these people to be rebuilt and after I paid someone to install the two pieces the total was about $250. Also...GM had a recall on front hubs and speed sensors...maybe your truck qualifies.