04 SRX Service Steering System
 

I have and 04 SRX and had a local Chevy dealer do an oil change, tire rotation service. About a month later I get a "Service Steering System" warning and take it back to the dealer. He said I need a new rack because the power steering actuator is bad and it's built-in...$1200. I refused the fix and left the dealer. After nosing around some I found out that the car came from the factory with different size front (P235/65 R17) and rear (P255/60 R17) tires. Could his rotating the tires have caused my power steering actuator troubles? I know the car is sensitive to tire sizes because of a "service stability system" issue we had in the past, and I wonder if the tire size difference may be enough to cause the power steering problem.