Yours is an 08 (3,1) machine is it not?
Works fine on 09 (4,1) and later machines, clearly for the 08 machines the fan codes are different.
No, the machine I "use" is a MacPro 1,1 recently burned to 2,1 status. And yes AFAIK we're dealing with three quite different versions of SMC. What works in one stands a good chance of not working in the other two.