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Hi all,

First time post so bare with me.
I am attempting to fix a 2003 RS6 Advant C5 BCY engine which was pulled apart and incorrectly slapped together. The PCV system was thrown together & as a result I have had to replace many broken parts and blown seals along the way. One of these parts was the auxiliary water pump under the manifold.
My problem is, now that the manifold is going back on, I can not for the life of me find the wiring connector that fits the electric pump. All connectors along the loom are accounted for except one square connector which I'm sure will make sense once I've put secured the manifold down. The connector for the pump is small and half rounded.
Is there anyone who could point me in the right direction? Either with a picture showing where the wire connects into the loom or even a wiring diagram. Any help would be super appreciated.

Weird. I Have owned my car since 2012. It was only 2 days ago that I found out that this pump existed. A non forum member was looking to purchase one.

Sorry I cannot help. But i am sure someone on here will be able to assist.

I can probably dig out a wiring diagram for you.

You sure that’s the right pump? I thought the part number ended 599 or 599A

/also parts starting 4D are usually (but not always) for the A8

Hi Ben. I also questioned that part no.
4D0203509J

Looking at a old post in 2006 with Matt and simonS4MTM contribution.
Two types of pump for our cars depending on the vin number
077121599
077121599A
Also mentioned was 078965561 which is the pump that Simon purchased.
But I don’t know what the differences are.

There are three codes listed as having that pump:
- PR:8Z5 (Not hot country, so probably BRV engine)
- PR:8Z6 (Hot country, so also BCY)
- PR:8Z9 (Super hot country, so also BCY)

All three are listed to use 077121599A. It's NLA but can be ordered from Audi Tradition.

There's no mention of that pump in Bentley's but I found an interesting mention in the diagram for "V51 : After Run Coolant Pump" ... not sure if that's the right one or not, please see image attached. Link to the part at AUDI Tradition:
https://shops.audi.com/en_GB/web/tradit ... 077121599A+

You have PM with more details

Yeah, it’s the after run pump. To stop the turbos cooking if you are an unsympathetic driver and don’t let your oil cool down before switching off.

Hi all,
Thank you so much for your replies!
I should point out that this pump is a brand new unit out of Audi Tradition, 077121599A is the part I ordered & what I've been invoiced for. The original pump had the electrics exposed & corroded so I figured the previous garage had not bothered to plug it back in when they couldn't locate a new one. I do have Elsa which has been a massive help and with a bit of homework I have discovered this:
My problem is the connectors are quite different. Maybe I am missing a length of wire with different ends??

Why has the pump in your pic got a different part number?

Looking at it closer, I think the part num visible in the pic is the one for the latch holding the pump.

That connector looks familiar. I'll be in the garage later and take another gander.

Sent from my SM-S918B using Tapatalk

I think you're correct there Astrosquirrel. I'm going to look into whether there is a missing piece of loom..

That makes sense.

I wonder if the DPO cut the old connector to solder the wires directly to the broken old pump.

FOUND IT!!
4B7971379A is the part number I need and it's available from Tradition. It just sucks that I'm on the other side of the world

Nice find! Do you have issues with shipping?

I tried to buy it myself but of all the countries listed, NZ is not there! To save time I have asked the dealer to supply those two connectors and i'll make my own harness. It's only two wires.
Astrosquirrel, could I please have a clearer pic of the EWD? I tried to zoom in but I'm going cross-eyed