[DannyM235]

I have been having some overheating issues with my M235i. I ended up checking the fault codes with BimmerLink and found these codes before I cleared them.

Fault Code 1A2004: Electric fan, control line: line interruption

After I cleared them and ran the error codes again I got the following:

Fault Code 801208: Fan output stage: Current limitation active

I did take a small clip of the fan during the time it started to overheat right before I got the engine overheated warning to shut off the engine which I turned off immediately once I got the warning. But can't seem to figure out how to upload it. I can upload photos but not videos.

I was also reading the coolant temp right before the engine was shutoff, it reached 129 C which is like 264 F. I first decided replaced the engine fan relay since it was only $45 at my local dealer. It however didn't resolve the issue. The fan never turned on after I replaced the fan relay.

So I checked the error codes again after replacing the relay with Bimmerlink again and this time the following fault codes came back:

1A2604: Electric fan safety relay, control line: line
interruption

1A2004: Electric fan, control line: line interruption

1A2002: Electric fan, control line: short circuit to ground


So after reading the codes again I ended up deciding to order a new cooling fan assembly from FCP for $855 with expedited shipping and tax, because the dealer quoted me $1065 for it. I'm just wondering why I had a code come on for the new relay. I made sure I connected one wire at a time to ensure I didn't place them in the wrong slot, I also had the negative battery terminal disconnected prior to replacing the relay, so I'm not sure what happened there. Apparently the M235i uses the 850 watt fan instead of the 600 watt fans used in non m sport vehicles, which is why the dealer stated it's price was so high. Anyone have any experience with this issue with their M235i, 335i or 435i, that have the N55.

[DannyM235]

Anyone have any experience with this kind of issue?

[XutvJet]

German electronics and BMW codes can be very weird. I have read of a handful of F series cars having similar issues and the fix was replacing the cooling fan assembly.

[DannyM235]

Originally Posted by XutvJet

German electronics and BMW codes can be very weird. I have read of a handful of F series cars having similar issues and the fix was replacing the cooling fan assembly.

Thank you for your response, I did see that another member with an m sport 335i had a similar issue and he did exactly that. I hope once I get a chance to replace it this weekend with the new assembly, I won't have anymore overheating issues.

[DannyM235]

For those who are interested, I did in fact have to replace the engine cooling fan assembly with a brand new version of the BMW 850 watt fan. It was a PITA to remove, but I was finally able to get it out by accessing the cooling fan assembly from both the top of the engine bay and the bottom with the engine with the undercarriage cover removed. When I reconnected the battery and tested to see if the fan would come on it still didn't kick on after reaching almost 190 F. So I decided to shut off the engine to prevent any overheating. I then decided to take the relay back to BMW and ask for a warranty exchange because I had a feeling the old cooling fan assembly might of fried the new relay I purchased last week. I was able to get an new cooling fan relay through a warrant return today. I went ahead and installed the new relay and reconnected the battery. I then cleared all codes and ran a data log via Bimmerlink, checking the coolant temperature and coolant temperature sensor reading as well as oil temperature. I went ahead and pulled over and popped the hood after about 7 minutes of driving around my neighborhood and seeing that the coolant temperature was rising; and finally the new engine cooling fan assembly kicked on. So it looks like the old fan did indeed need to be replaced and the new relay being damaged by the old fan was the reason it was not turning on. All in all the repair came out to almost exactly $900 with the new OEM BMW version of the 850 watt cooling fan assembly and a new fan relay. You could get both parts at FCP euro so you can have the warranty and the fan is about $265 less than at the your local BMW dealership, I just personally bought the relay locally as the initial starting point of this repair because my local BMW had it available for pick up the next day for me for $45. Pics of the new fan compared to the old fan, the new is lighter than the old by the way. The part number for the fan relay is below on the last image for those who are interested. Links to both OEM BMW parts below.

https://www.fcpeuro.com/products/bmw...ve-17427640513

https://www.fcpeuro.com/products/bmw...0a-61369198302

[Polo08816]

Originally Posted by DannyM235

For those who are interested, I did in fact have to replace the engine cooling fan assembly with a brand new version of the BMW 850 watt fan. It was a PITA to remove, but I was finally able to get it out by accessing the cooling fan assembly from both the top of the engine bay and the bottom with the engine with the undercarriage cover removed. When I reconnected the battery and tested to see if the fan would come on it still didn't kick on after reaching almost 190 F. So I decided to shut off the engine to prevent any overheating. I then decided to take the relay back to BMW and ask for a warranty exchange because I had a feeling the old cooling fan assembly might of fried the new relay I purchased last week. I was able to get an new cooling fan relay through a warrant return today. I went ahead and installed the new relay and reconnected the battery. I then cleared all codes and ran a data log via Bimmerlink, checking the coolant temperature and coolant temperature sensor reading as well as oil temperature. I went ahead and pulled over and popped the hood after about 7 minutes of driving around my neighborhood and seeing that the coolant temperature was rising; and finally the new engine cooling fan assembly kicked on. So it looks like the old fan did indeed need to be replaced and the new relay being damaged by the old fan was the reason it was not turning on. All in all the repair came out to almost exactly $900 with the new OEM BMW version of the 850 watt cooling fan assembly and a new fan relay. You could get both parts at FCP euro so you can have the warranty and the fan is about $265 less than at the your local BMW dealership, I just personally bought the relay locally as the initial starting point of this repair because my local BMW had it available for pick up the next day for me for $45. Pics of the new fan compared to the old fan, the new is lighter than the old by the way. The part number for the fan relay is below on the last image for those who are interested. Links to both OEM BMW parts below.

https://www.fcpeuro.com/products/bmw...ve-17427640513

https://www.fcpeuro.com/products/bmw...0a-61369198302

What was the hardest part to remove the radiator fan? I've removed it on a F25 X3 N55 but not on my F30 335i RWD yet.

[DannyM235]

Originally Posted by Polo08816

What was the hardest part to remove the radiator fan? I've removed it on a F25 X3 N55 but not on my F30 335i RWD yet.

The hardest part getting it out is due to the notch on the drivers side tends to hit the upper radiator hose connection and the intake tubing also gets caught on the fan assembly as it's being removed. But guiding it out from below is what helped me get it out of there because it was not possible only from the top at least not for me. There is also a small locking tab that keeps the assembly in place that has to be pushed in with a slim plastic trim tool or a flat screw driver on the drivers side right below the upper radiator hose connection before you can attempt to remove the cooling fan assembly at all as well as one mounting bolt on the upper passenger side and one to two bolts holding the transmission cooler to the fan assembly depending on your vehicle model and series's. I only had one mounting bolt for my transmission cooler on my M235i. Just go slow because things can break easily if you try and force it out; luckily for me I didn't break anything during the removal and installation but it did require some patience and some time for me to get it out. It wasn't a quick job, like it would have been on a domestic brand vehicle, this took me a few hours to get done. Something very important is to also use a clean microfiber or shop towel to stuff in your intake tube to ensure you don't drop any tools or hardware down there. A magnetic try and extendable magnetic tool are your best friends for this job in case your drop anything in the engine bay while working on it which can tend to happen.