ECM on my 2007 Dodge Durango SLT 5.7 V8 Hemi

What is your question?

I just found out today from a repair shop that my 2007 Dodge Durango SLT 5.7 V8 Hemi needs an ECM replacement. They came to this conclusion after I brought it in for a check engine light with error code readings (B166B and P3449). The vehicle has been running beautifully, no stalls, no jerking, the engine starts up smoothly and I haven't had any problems. They diagnosed a fuse as the problem behind the B166B error code, and a bad solenoid 7 circuit behind the P3449 code. After replacing the solenoid 7 circuit, they were unable to clear the codes and told me that the ECM will need to be replaced. Something doesn't seem right since the vehicle has been running like a champ. They quoted over $1000 to replace it on top of the $1000 they are already charging for the error codes and other services. My question is, how easy is it to replace the ECM on this vehicle, and where is it located in the engine? Thank you for your help.

What makes this problem better or worse?

Engine hasn't had problems, check engine light just came on

How long has your 2007 Dodge Durango had this problem?

1 week