You will need to clear the air bag SDM Module which is located under the drivers seat. Its held in place with 3 10mm bolts. The 03 will have one single yellow plug with a lock pin that holds the lock release for the plug. You can get this module out without removing the seat but its a pain.
So after removal you will need to find someone that can clear the sdm as the Factory Scan tools can not do this. I clear them daily but im located in St.Louis. You can find many mail order places that will do it or check CL and see if someone in your city offers that service.
If you opt for replacement of the new SDM you are looking at around $320 to $400 for the part and then will have to have someone with a TECH2 config it to the car. You will run two separate procedures to lock the primary key to the bcm from the SDM.