Citroen C5 X7 cabin blower controls does not work + A/C not working

[Kupsberg]

Hi all!

Vehicle: Citroen C5 X7 2.0 HDI FAP 136 SW (year 2008), mileage ~420 000km.

I decided to make a new thread on this as it is really not a thing I have been able to resolve. There are two issues which I belive are somehow related to each other. This is my second car and I use it only few weeks a year when towing caravan or snowmobiles on a trailer. Thus focus on AC issues etc has not been hugely important. But now I'm planning on taking her to middle europe for 12k km roundtrip with my caravan and would like to fix the cabin blower at least.

Okay, so:

1. Once I start the engine the internal cabin blower reacts to (your) alterations in speed from the IC controls on dashboard, for 30 seconds and after that she decides the blowing speed on her own. The windscreen clearing function does nothing to the blower speed. The fan does blow lets say 3/8 speed of full power pretty much constantly. I have replaced the controlle module in the footwell at 2020, as before that there were no blowing what so ever. After that the blower started to operate as is now and occasionally there has been periods when it even responds to the commands from the dashboard.

Q:
1. Could it still be the control module?
2. What else should I check regarding this?

2. Secondly the A/C does not work and engine fan operates weirdly, which I have another thread opened few years ago and is still an issue, with which I have managed to cope so far. Would be nice to have it working as well. This we don't need to dive into if not decided so from staff. (viewtopic.php?t=72235)
Known things:
-No engine fan speed can be observed in Diagbox (line broken?)
-No low speed functions working on the engine fan
->All wiring from engine fan to ECU and BSM has been checked using contact analysis (beeper)
-Only possible culprit seemed to be a relay on PSF1, which was unchangable (inside the BSM)
-New BSM installed (from crashed -14 vehicle), no change
- High speed functions fuse has been blown once, after changing it high speed started to work properly again
- Last summer high speed function malfunctioned again on a very long hill climb, no blown fuse but acts as one had burnt. changed anyways. Started to work as far as no more overheating alarms.
-> symptoms: Fan runs on high speed ~30 seconds, shuts itself off for 15 seconds and then starts blowing on full again for 30s.. And under heavy loads the cooling is insufficient when towing caravan.



Currently there are some fault codes present, and to list a few:

F72F Air blower fault (under Air conditioning)

And if I remember correctly these were under ECU:
P0462 CAN communication
P0691 Fan high speed control
U1109 CAN communication
P0215 Injection system supply relay
P1351 Pre-Heating relay circuit (possibly 2/4 of pre heating relays are gone dark, still starts though well >-15°C)
P1403 Additional heating circuit 1 (I think this comes from the installation of aftermarket heater (webasto) to replace the "factory installed"

All help welcome!

-J

[PaulC5]

Was the new part you fit in 2020 for the blower speed control a Citroen supplied one or a copy part ? If a low cost copy one it may not be working correctly.

[Kupsberg]

Hi Paul,

Thanks for you input! I think you are on to something! The part installed 2020 was Ridex so pretty much cheapest you can get. I've looked in to this and I agree that most fingers point to the direction of the blower control module.

My problem is that I don't know which one to order/trust! There would be Hitachi (132514) one on Aeromotors on ~45€ which I'm thinking of. A genuine new part would be ~120€ from EuroFrance24. I have understood that the original unit is either BEHR or MAHLE made. But neither are available anymore on their parts numbers.

HELLA BEHR 5DS 352 320-011
MAHLE ABR21 000P (now only ABR21 000S available, anyone know if this fits or not?)

Any advices regarding which one to choose? Would the Hitachi one be worth a go?

-J

[PaulC5]

A search suggests the Mahle ABR21000P is still available https://www.ebay.co.uk/p/11039417116

[Kupsberg]

Hi,

The ABR 21 000P seems to be available only in UK ebay and its too much of a hassle ro order from there after the brexit.. Would not arrive on time before leaving to my trip next weeks saturday..

I ordered a Mahle Behr ABR 21 000 S, as I thought it might be just a later revision of the -P ending version and it is referring to the same oem part number.

It arrived today, just tried it. Blowers screen clearing function now does something, although I think it's only 70% of what my dad's C5 blows at full. The fan speeds still does not work. If you turn down the fan speed to zero the blow speed is constant and just turns a bit colder.. Can't say anything about the AC as its +5°C outside..

Any suggestions?

[Kupsberg]

Back to report.

It turns out that the Mahle Behr ABR 21 000P is pretty much the only suitable aftermarket part for replacing the cabin blower control module to Citroen C5 X7. And apparently it has been discontinued as it has been for sale also here in Finland on the Citroen-dealerships. You might spot some on Ebay from older stock, but new are not available to my understanding.

Units I have tried and which haven't worked:

Mahle Behr ABR21 000S
Ridex
Krios 10.6045
NRF

So to help you fellow members: Don't try to go for a shortcut on this. Please, you will just waste your money and time. Order new or used OEM cabin blower module. I wasted years (well summers of few years) to this and I started to look and fix the issue from the wrong end. I changed the engine fan becouse the low speed function did not work, used a Ridex part for this btw, and it works fine now with the correct cabin blower control module. So the low speed probably was fine on the previous engine fan as well.. But right after changing it two years ago Ridex did not have any effect on the low speed function. I Also changed BSM as after few long days of diagnostics on the wiring looms of engine fan, ECU and BSM last summer I could not find anything wrong with the system. Only option I could see from the wiring schematics was some relay on the PSF1 (BSM) which was not changeable and thus ended up changing the whole BSM. At least I now have a spare BSM if it goes on the road..

Now I wonder if the high speed side issues on the engine fan has also been caused by this incorrect interior cabin blower control module, as I have not found nothing wrong with it either and it still started to cut out on cooling on the long uphills in Norway when towing a caravan, pretty much every year. I'll try to remember to report this later here as well.

Hope someone finds these findings useful in the future.

-J