What am I looking at?

I had been getting a 2722 low pressure sensor code for a few days and decided to get it taken care of. Following @flip's post (http://www.m3post.com/forums/showthread.php?t=694148). I got the filter box taken out and the first thing that I noticed was a severed wire on top of what looks like a fluid pump of some sort. can anyone tell me what the "pump" is and what issues it could be causing? I plan to solder the connection back up shortly but I am kind of curious why it wouldn't be throwing any codes.



Thanks

I tracked it down on realoem.com looks like it is an additional water pump.

Double check on this one but my guess it's the Auxiliary water pump. It is the pump that controls the flow of hot water to the heater coil inside the cabin. Turn on the heater and you should have very little to none.

M3Bimmer77 wrote

Double check on this one but my guess it's the Auxiliary water pump. It is the pump that controls the flow of hot water to the heater coil inside the cabin. Turn on the heater and you should have very little to none.

I did some more digging around and it sounds like this is an electrically driven water pump for when the engine is powered down. Basically if you want to keep the heat turned on while the engine is off this pump will run off of the battery and keep cycling coolant between the block and the heater core so that the air keeps blowing hot. I was able to re-solder it and verify that it was working by getting the car up to temp, turning on the heat, and then shutting off the engine.

It is kind of a cool feature but now I wonder how many more systems there are in the car that I am completely oblivious too.