So I bought an 07 335xi with this problem. The water pump had been recently replaced but only kicks on when removing the 50A fuse from the box under the hood and reinstalling. This is after the car is started. I've checked all the wiring and the other fuses in the cabin. The only code I'm getting is 2E7C BSD bus communication fault which I'm not sure is related or is just being tripped from the fuse trick. The car runs great otherwise but popping the hood to remove and replace the fuse is certainly annoying and not a long term solution. Any ideas on this would be greatly appreciated.