aux water pump not working W205 220d

[Sergiuu]

Hi guys,
It looks like for long time my aux water pump have stopped working, i have seen coolant stain around the Aux Expansion Tank
Today i had the Expansion Tank + Cap + aux Water pump changed but still the pump not working
I have checked the fuse box under the bonnet (next to engine) and i can see that The Fuse for Electric Coolant Pump (107) and the Relay for Coolant Pump (P) weren`t there
So how the pump should be working without the fuse and relay?
On the diagram is stated that these 2 should be available with the engine 274.9
Anyone had this problem before and has some answers ?
Thank you

 

[Shergill]

Hi guys,
It looks like for long time my aux water pump have stopped working, i have seen coolant stain around the Aux Expansion Tank
Today i had the Expansion Tank + Cap + aux Water pump changed but still the pump not working
I have checked the fuse box under the bonnet (next to engine) and i can see that The Fuse for Electric Coolant Pump (107) and the Relay for Coolant Pump (P) weren`t there
So how the pump should be working without the fuse and relay?
On the diagram is stated that these 2 should be available with the engine 274.9
Anyone had this problem before and has some answers ?
Thank you

Hey. I've noticed that this auxiliary water tank was always empty despite filling up a few years back. Today was doing a coolant flush and again thought I'd explore it again. A few years back i had this diagnosed by a garage who reported no leaks under pressure but the pump was not working even though they put in a new one. In the end they gave up and said need to see mercedes as no info available. Today I noticed another thread and decided to look at fuses. I also noticed that I had no p relay or 107 fuse so have the same issue with my 2015 c250 diesel. This can't be coincidence. I thought maybe they forgot to put back when they changed the pump but found your post. Did you fit the Relay and fuse and did you ever get it working as wondering what to do.

 

[Shergill]

My only thought now is maybe this isn't meant to be work and is just installed as part of the manufacturing process.
The Tank has been empty despite filling for years and changing pump and being tested for pressure.
The image shows what it should look like

 

[Shergill]

Hi guys,
It looks like for long time my aux water pump have stopped working, i have seen coolant stain around the Aux Expansion Tank
Today i had the Expansion Tank + Cap + aux Water pump changed but still the pump not working
I have checked the fuse box under the bonnet (next to engine) and i can see that The Fuse for Electric Coolant Pump (107) and the Relay for Coolant Pump (P) weren`t there
So how the pump should be working without the fuse and relay?
On the diagram is stated that these 2 should be available with the engine 274.9
Anyone had this problem before and has some answers ?
Thank you

Any thoughts on this mate?