Error P1622 on 1998 740i

[dbill0215-7]

I have this error show up and want to know what I can do to get it to go away. Is this a faulty theromostate?

[marti5]

Do you have a problem with the car in anyway?, if not clear the code and see if it reappears P1622 is to do with the coolant control circuit but can be one of many things even a loose connection.

[dbill0215-7]

Yes I clear it and it comes back in anywhere from 1 hour to 3 days. While the car never overheats, it does get hot enought that I have to add some coolant which also leads me to believe it could be the thermostate. Can you test the theromostate the old way by putting it in a pot of hot water and see if it opens or does the electrical connection prevent this. I have never removed it so I am not sure what it is like. Only looked at the pictures of the part. Thank you for your response.

Bill

[marti5]

Im sure on your model its eletronic, there's one way to tell if its working, get up to temp,if the top rad hose is hot/warm and the bottom hose is cold then the stats dead if however they are both hot/warm its fine ...