Xoutpost.com

Xoutpost.com (https://xoutpost.com/forums.php)
-   X5 (E53) Forum (https://xoutpost.com/bmw-sav-forums/x5-e53-forum/)
-   -   IHKA/AUX WATER PUMP (https://xoutpost.com/bmw-sav-forums/x5-e53-forum/111518-ihka-aux-water-pump.html)

Henrym3 02-08-2020 06:02 PM

IHKA/AUX WATER PUMP
 
Some months ago the aux water pump stopped working. Ignored it cos it was summer, have now fitted new one which puts coolant into header tank but at about 25% flow. Checked voltage at plug and it’s 4.65v Put 12v to motor and it runs like a trooper. Question does the IHKA regulate the voltage or is it faulty. Never seen more than a trickle all the times I’ve looked. Have put a separate earth to the plug without any improvement. Thanks in advance.


Sent from my iPad using Xoutpost.com

Clavurion 02-08-2020 06:23 PM

Sounds strange. There should be direct battery voltage from IHKA to aux water pump when activated.

aureliusmax 02-08-2020 09:23 PM

the low voltage is really a problem. it could be a relay or transistor driver that went bad. do you have access to the wiring diagrams ?

Clavurion 02-08-2020 10:41 PM

There are no relays. It must be a FET on IHKA board.

https://www.newtis.info/tisv2/a/en/e...r-pump/hDKLnGe

andrewwynn 02-09-2020 12:32 AM

I thought I saw my foxwell had a test setting for 30% etc speed. I have a feeling you are seeing a PWM reduced speed on purpose.

If the heater cores stay warm at idle your aux pump is running fast enough.

Henrym3 02-09-2020 09:01 AM

Interesting, I thought that maybe because I didn’t change it when it stopped working and the fact that there is no fuse to blow that I had burnt something out in the IHKA. The fact that there are no heater problems would support Andrews theory. It’s just that I always thought it was either full flow or nothing.


Sent from my iPad using Xoutpost.com

Clavurion 02-09-2020 09:48 AM

A quote from BMW IHKA document: "The auxiliary water pump is powered directly from the IHKA control module through a final stage output." So indeed it could be PWM controlled, not just on/off. Unfortunately there was nothing more specific on the matter.

Henrym3 02-09-2020 10:11 AM

Thanks for that information, when I first put it in even though there was no flow I knew it was running by feel, the right side had no heat but I had read on here to rev to between 3/4K revs a few times to perhaps shift an air lock, this restored the full heating and I then started to get the roughly 25% flow. Not had in issue since (6 weeks)


Sent from my iPad using Xoutpost.com

aureliusmax 02-09-2020 03:36 PM

for some reason in my mind i was thinking the aux washer pump and not the aux coolant pump .
i would perform a resistance check of the harness. from the wire in the ihka harness to the signal wire from the connector to the pump. should be less than 1.0 ohm or very near. Anything more could indicate a problem with corrosion or internal break of the wires (think only one strand carrying current) which would really drop the voltage a whole lot.

wpoll 02-09-2020 07:11 PM

Or check the voltage with an oscilloscope - that way you can spot the PWM signal (if it IS PWM).

Don't have a 'scope? Then try your digital multi-meter on the frequency (Hz) range. If you get nada, it's likely DC line but if the meter reads a frequency of something like 1000HZ (1kHz) then its a PWM circuit. :thumbup:


All times are GMT -4. The time now is 03:41 PM.

vBulletin, Copyright 2024, Jelsoft Enterprises Ltd.
SEO by vBSEO 3.6.0
© 2017 Xoutpost.com. All rights reserved.