You probably have already checked this, but just in case.....
On top of the left shock tower, there is an in-line fuse inside a plastic cover. The fuse is a flat piece of metal held in place by 2 screws.
I had a similar problem a few years ago and the dealer wanted to replace the computer/control unit. The mechanic already had the part in his hand, ready to replace it when a second mechanic told him to check the fuse.
Problem solved, I save a bundle.