OE is Original Equipment, BMW parts.

OEM is Original Equipment Manufacturer, means also makes OE parts.

Aftermarket is neither.

Go for OEM.


https://www.fcpeuro.com/products/bmw-land-rover-hvac-blower-motor-control-unit-behr-64116923204b


OE is $112. OEM is $39.

 

I bought an OEM Sitronic FSR, originally made for BMW, made by Valeo, who ultimately sub-contracted it to ACM. How's that for a supply chain.

To answer your question, I think OEM works great! I wouldn't venture into the aftermarket.

<img src="https://farm8.staticflickr.com/7763/16751127044_67de8d5f6a_c.jpg" width="800" height="600" alt="image"></a>

 

I think I have the same problem. It will work sometimes, and sometimes it will not come on at all. And my window switch failed, now I cannot turn on the A/C or wind down the window, what luck! Did you replace the FSR, did it fix it for you?

 

OK, an update with new data....

Beginning in late fall the problem essentially went away. How convenient. Recently it has resurfaced. It seems to act up in warm weather.

I don't think it's the FSR. There are no symptoms to suggest that's it.

In the morning, when I first start the car the fan works fine, often throughout my 40 minute commute. Later in the day (lunch sometimes or usually on the commute home) it tends to work for about 10 minutes then quit. In the past it would cut out for only a few minutes (sometimes seconds) and come back on. Lately it has taken longer. Yesterday it did the usual work for 10 minutes and cut out. When I stopped for gas it started working again and worked fine the rest of the day. This morning it worked fine. On the way home, however, it got bitchy again. Worked for 10 minutes and cut out. I turned the IHKA off for about 10 minutes and turned it back on and it worked for 10 minutes and cut out again, this time for the duration of my trip, regardless of the little tricks I've employed in the past to restart it. I turned the AC off and on, varied the fan speed control (the IHKA shows the speed the fan should run). Nothing. When I turned off the AC I would get cool air drifting through the vents, but when I turned the AC back on, it would stop.

So, for sure the problem is one during warmer temps (it was 89F today so the commute sucked).

I suspect the IHKA could be bad, figuring when it heats up it cuts out and when it cools back down it works again.

The other suspect is the AC system itself. It could be perhaps low on refrigerant and the pressure switches are saying "no." Or it could be a bad expansion valve. I suspect the rest of the AC system less because it works fine otherwise. I may stop someplace tomorrow and have the 134a checked and topped up if necessary.

I have another IHKA from my 328i, but looking through Bentley's it appears the IHKA needs to be coded to the car and that is currently outside my toolset.

So, armed with this new data, do any of you have anything more than a WAG regarding what the culprit is?

Normally I'd just take it to a trusted shop and have them take a look at it, but I have a crazy-@$$ week with meetings ALL day tomorrow and court testimony Wednesday regarding the guy who ran into me last summer with a cement mixer. Then I have meetings all day on Thursday and Friday is the last day of the month, which means I'll be swamped. Saturday will be my first possible chance to have a shop check it out, but I'm running 17 miles in the morning and don't know when I can get to a shop. Like I said, crazy-@$$ week. And the following week I'm closing the books at work. So, any initial help I can get beyond a WAG will be greatly appreciated.

 

Concur, it doesn't sound like the FSR. It does sound like the IHKA could be at the heart of the problem. But, please remember that the IHKA gets inputs from various sensors. If the symptom occurs when using the AC it could be a pressure sensor (R143a charge level), an evaporator temperature sensor (shuts off the AC to prevent the evap from icing up). However, it could be IHKA If it happens during heating and AC use. I'd be tempted to do an electrical system reset to see what happens. It's a BMW approved procedure. I've seen it cure issues that stumped people.

- disconnect the ground cable from the battery
- disconnect the positive cable from the battery
- short the 2 cables together go at least 10 minutes
- reconnect the positive cable to the battery
- reconnect the ground cable to the battery (sparks are ok)
- reset the clock.

 

Oh, that's definitely worth a try. It's free and doesn't take long.

If I get out of court reasonably quickly (my testimony shouldn't take long), I plan to stop by my favorite indy shop and have them check for any diagnostic trouble codes stored for the IHKA. It's just frustrating being SO jammed up time-wise this week.

My thoughts are like yours that it's possible it's due to readings from some sensor(s).

I have been trying to remember if it has ever done this without the AC on. I cannot for the life of me remember. If it only does it with the AC on, that would seem to suggest an issue in the AC system I think, although it could also just be the electronics overheating.

 

My HVAC had the same symptoms. Worked fine if it was cool outside. AC would not work reliably when it was hot. Sometimes it would run fine, sometimes not at all, sometimes the fan speed would vary even when it was set to manual speed. I replaced FSR - problem solved. I can't say if will solve your problem, but it did mine.

 

I don't think the IHKA is coded and is plug and play. I'm having the same issue and replaced the FSR with a genuine one and it won't work for several days. I also might think it's the blower motor going but I'm not sure I want to go there yet.

I get a weird noise revving up and down and almost like it's rubbing/clicking in the housing.

My weird thing is, I hit a bump/pot hole it will come back on.

 

Thanks for the input guys.

New data today....

This morning was cool enough to drive to work without AC. Got in the car after work and left the AC off. Same symptoms. The fan ran for a few minutes then quit. I turned off the fan for a few minutes and then back on and it worked again. For a few minutes. Then I turned on the AC. Same thing.

So, I don't believe it's AC related.

My fan speed does not vary from the setting. So, I'm still doubting the FSR. Still, it is a possibility.

According to Bentley the IHKA is indeed coded to the car.

If the control module is replaced it must be recoded using BMW scan tools DIS or MoDiC.

 

You've done a lot of diagnosis on this. I would have arrived at a different conclusion however. By now I would have replaced the FSU and/or blower, both of which cause intermittent running of the fan based on the experiences I've read here and Bimmerfest. My convertible's FSU failed the same way.

Bentley must be mistaken. If it does need coding then it presents with no observable symptoms. Delmarco's HVAC thread and personal experience tell me HVAC control panel swaps are a non-issue.

 

Oh yeah.... It was certainly due to be replaced. It was an original (or at least very early) FSU.

One other thing. I read some debate about what brand was OEM. At one time it was Behr. However, this Behr FSU (as well as the original FSU in my prior E46) was also labeled Denso.

 

I've fixed my fsu on my old x5 and now my convertible m3. It's pretty easy but then again I work with electronics repair so maybe that's why. The issue with my fsu on my convertible was that the fan would not blow hard enough. I tried to remove it (but I ran out of time) and next time it would not blow at all. I banged it and it worked lol so next day I made the time to take it out and repaired the cracked joints. Lo and behold issue solved. Fan comes in full blast now.
As for my e53 x5 the issue was that it would come on and even if you turned it off it would stay on.

 

Mine was the AUC sensor that attaches to the fan shroud that detects carbon monoxide. Mine was unhooked all together. Because I hadn't reinstalled the shroud my fan gave your exact symptoms. Put it back in and problem solved.