w210 climate control funk
 

Sometimes it regulates temperature correctly, sometimes it doesnt. Hot air comes out when cold should and vice versa. Always blows hot/cold air when on "HI" and "LOW". Compressor and A/C work fine. Ideas?

Sounds like the classic aspirator motor problem. Make sure that air is being drawn across the two little vents near the dome light.

You also need to read Steve B's article on diagnosing climate control systems. Here's a link: http://www.continentalimports.com/ser_ic40142.html Run through the actual values test to see what inputs and outputs are occuring.

- JimY

I did the diagnostics, I have error codes 416 (coolant circulation pump) and 459 (series interface connection problem).. I pulled the climate control unit and removed and replaced the connectors several times, still came up with the same code.

Also, during the data monitoring function, I have 0 volts at function 23, terminal 58d.. Does any of this mean anything to anyone?

TTT.. Ideas? Climate control seems to function normally until about 15 minutes into the drive.. then has a mind of it's own. I want heat, it puts out old air. I want cold air, it puts out heat, etc.

It could be the duovalve that is stuck sometimes, in my car it often happens when I've been driving a while and then for example stop the engine for a few minutes after that I will get hot air from the side vents and cold at the center vents, usually it helps to knock a little on the duovalve and all is up to date again.

The duovalve controls the heat water to the radiator and is default open, if the AC control unit finds out that it has to be closed it does so by putting voltage on the duovalve. It's possible to use grease to make it work properly, preferably vaseline or some other water resistant stuff, you can open it by using a small torxdriver and it's located on the right side of the engine compartment near the blackbox containing all electronic boxes or follow the water lines an you'll find it.

My car also have these errorcodes but I have disconnected the electrical coolant circulation pump since I've read that if it's stuck or defekt it could generate a high current that may damage the climate control unit. The errorcodes will remain in the system until they are erased. It's possible to erase the errorcodes by (I think) pushing both auto buttons at the same time for a couple of seconds when you are in the reading errorcode mode.

Morgan