Trans fail safe prog
 

so i just got back from vaca after driving 300 miles without a problem and after i wash the car the trans fail safe message is showing along with the service engine soon light. The car is also shifting real hard for the first 3 gears up and down but it does go through all 5. Any thoughts? i read the alternator could do this.

Check your charging system as a first measure.

Did you hose under the car and get the trans wiring loom connector wet? :D

You might want to give some more information to get the correct help. Year and engine configuration.

It's a 2006 3.0, I hosed the motor off but nothing crazy

Pop the trans splash shield off, unplug the trans loom connector from the trans and make sure it is totally clean and dry inside - a hair drier on a low setting might help here. The errors you have are known to be caused by moisture and dirt in the trans loom connector.

http://www.bimmerfest.com/forums/att...1&d=1440279609

There are other causes to (alternator, like you suggest. Which also don't like getting wet) but the hose under the bonnet is a smoking gun. :D