Deleting Auxiliary Water Pump?

[Titaniu//M]

Hi all,

Does anyone have experience deleting the Auxiliary water pump under the intake? The Dinan intake on my car barely clears it, and the relocation bracket Dinan provided does not work well. I'm thinking of buying the version of the heater valve from the CSL that deletes the auxiliary water pump. If I replace #1 with #2, I'm wondering what issues I could experience. From what I can tell, the auxiliary water pump simply pumps coolant through the heater core at a faster rate, so if I delete it, does the car interior just heat up slower?

From my research, 3 versions of this part exist on S54 platforms


1. P/N 64118369807 - found on all North American E46 M3s and S54 powered Z3Ms - heater valve w/attached auxiliary pump



2. P/N 64118369805 - found on E46 M3 CSL, non-M E46 3-series, and X3 - heater valve only, no attached auxiliary pump



3. P/N 64118369806 - found on Z4M coupe/roadster and some E9X platform cars - auxiliary pump only, no heater valve



Thanks in advance!

[Obioban]

I’m running the non M/CSL version. No notable difference.

I did code the climate control module (I think it was that) for the alternate pump.

[Titaniu//M]

I’m running the non M/CSL version. No notable difference.

I did code the climate control module (I think it was that) for the alternate pump.

Awesome, thanks for the quick response. Any suggestions on who can code this in for me?

[repoman89]

I'm running it as well, coded it as described in Obioban's diy on the old forum. Works fine and clears the CSL airbox. I even snipped off the extra plug. Anyone know the other endpoints of those wires by the way? I'd like to pull them ...

Edit: One wire ends pin 6 on the plug on the back of the heating controls:

https://www.newtis.info/tisv2/a/en/e46-m3-cou/wiring-functional-info/body/heating-air-conditioning-functions/temperature-control/water-valve/pNoohMP

https://www.newtis.info/tisv2/a/en/e46-m3-cou/wiring-functional-info/body/heating-air-conditioning-functions/temperature-control/auxiliary-water-pump/b6Ndy73

The other makes its way to fuse 62 in the glovebox, but so does the water valve wire, and they're the same colors ... and it's unclear where they join based on the wiring diagram.

[Obioban]

I'm running it as well, coded it as described in Obioban's diy on the old forum. Works fine and clears the CSL airbox. I even snipped off the extra plug. Anyone know the other endpoints of those wires by the way? I'd like to pull them ...

Yeah, I wish I could remember what I did... used that forum a lot to look up my own stuff :P

[Stepstools]

This thread has been enlightening so far. Didn't even realize we had an aux water pump. Maybe this is the cause of my elusive "communication with aux heater" IHKA code. Just checked the connections on the pump and they seem fine, maybe a coding option is messed up. Guess I'll mess around with them later today and see what I can find.

[EZE]

I’m going to do the swap when the regular water valve comes in but looks like you just have to code the water pump out in the ihk module.

page 22

https://ncs-expert.com/wp-content/uploads/2013/06/FSW_PSW.pdf

will post if it works okay with no codes

[Titaniu//M]

I’m going to do the swap when the regular water valve comes in but looks like you just have to code the water pump out in the ihk module.

page 22

https://ncs-expert.com/wp-content/uploads/2013/06/FSW_PSW.pdf

will post if it works okay with no codes

I never coded mine and a year later still have no codes

[Obioban]

I never coded mine and a year later still have no codes

I would suspect it functions better when the car knows what hardware it has, whether it's throwing codes or not.

[nextelbuddy]

I would suspect it functions better when the car knows what hardware it has, whether it's throwing codes or not.

I think on the old forums terraphantm had mentioned that on the E46 M3 the auxiliary water pump portion even though it was installed was never actually coded to be used by the HVAC controls module. Even though it's wired in to the body harness I don't actually think it does anything compared to say the E39 M5 and the X5 e53 where it actually does operate like it's supposed to.

My E46 ZHP that's been converted has the non-M heater water valve and I've had both HVAC control modules from the facelift cars and pre-facelift cars and not had any issues with it.


***Edit I was wrong sorry Terra! Looks like the hvac module in the m3 specifically is coded for the aux water pump and will display an error code in the hvac module itself of the aux water pump is not present though people that have swapped in m3 hvac modules into non Ms didn't notice any issues with their heat or ac despite the error being present I'm the hvac module itself.

Should be able to use ncs expert to recode the hvac module to disable the aux water pump portion or swap in an hvac module from a non M.

[Obioban]

Yeah, I’m running the non M version on my coupe, as well... but coded the car accordingly.

[Thonas]

I am also running a non M single cylinder unit with no issue and no codes.

[old///MFanatic]

I am also running a non M single cylinder unit with no issue and no codes.

Oh that’s great! So you checked the connector voltage and no issues. It was just the valve bad in your other thread, good news.
And nothing coming up prior or since in codes like

[EZE]

I never coded mine and a year later still have no codes

Not even anything in the shadow memory?

[Obioban]

The fact that it can me coded makes me assume something changes— otherwise they wouldn’t bother having an option. Lack of codes doesn’t mean everything is optimal.