My E89 Z4 got issues when wet

[eugeneparsons]

Hello,
I have a z4 E89 that gave error about parking brake, engine ecu, gearbox, dashboard and iDrive only if is raining. Yesterday I tried to remove the parking brake ecu and the car shows the parking brake warning for few seconds but after that was normal. In the past the battery compartment was wet but this problem now is solved. I think it’s something related to Can line but I’m unable to find the issue. Any idea?

 

[AnubisZed]

Well I'd say you're certainly going in the right direction. Almost certainly a canbus issue, BUT....
How old is the battery? If it's a genuine BMW one then there will be a date code stamped into the top of the negative terminal. Worth looking into first before searching for the canbus issue. The problem with canbus issues is that virtually everything electrical on the car has a twin canbus line going to it, so it could be anywhere.
If you've put a code reader on it, what codes did you have?