Toyota Repair: ABS light on 03 Corolla, eibach prokit, rims tires

Question
Recently, ABS light turned on for my 03 Corolla.

Information about my car:
- Purchased in January 2003
- Replaced the springs to drop the car by 1.1" in April 2003 (Eibach prokit)
- Replaced front and rear sway bars in May 2003 (Hotchkis)
- Replaced original 15" rims (195/65/15) with Toyota Matrix 17" rims (215/50/17) in July 2006

The ABS light started to turn on 6 days after I changed the rims/tires.
I've read the questions/answers for others on this site and it sounds like this is caused by the malfunction in one of the speed sensors.
The strut was taken out only when the springs were replaced and that's over 3 years ago.
It started only 6 days after the rims were replaced, but I'm guessing it's only a concidence and not caused by the rims.
The mechanic said it's because of the difference in diameter of the rims/tires, but it's only 1.9% larger than the stock spec.
I checked the brake fluid and it's full.

ABS light is on as soon as I start the engine.
It stays on until I turn the engine off.
One weird thing is that if I let go the side brake before turning on the engine, ABS light goes off after a few seconds.
But it goes on as soon as the car moves an inch.

I'm guessing the only thing I can do now is to take it to the dealer.
I wanted to know if there is anything I should do prior because my warranty is already expired (3 years 8 months and 35k miles).

Thank you in advance for your help.

Answer
I don't think that the changing of the rim/tire size has anything to do with it since the computer reads the revolution of each wheel and compares the readings of all the wheels, as long as all of the wheels turn at the same speed there is no problem, since all the wheels are the same this is not the problem, the problem is the computer sees one wheel rotating at a different speed than the rest for some reason, probably because of a wheel speed sensor failure, the dealer should be able to connect a diagnostic scantool to retreive the trouble code in the ABS system and then go from there and by the way, your warranty was void as soon as you installed all that aftermarket equipment.