HELP!! 2005 BMW X3 3.0L - Auxiliary Fan not working...

[louiemondo]

I have tried everything. I have replaced the fan, the sensors, the fuses, the relays, etc. I even had the ECU diagnosed by SIA Electronics in Illinois and it checked out to be in perfect working condition. What am I missing, what else can I try? I would prefer not to junk the car, but I am at my wits end. The tech at SIA said it may be a software issue, is there another way to have this checked besides bringing it to the dealer? I have already dropped around $1300 into this issue... any help would be greatly appreciated.

This is what I have replaced:
Radiator Fan Assembly
Temperature Sender / Sensor (in lower hose)
Air Temperature Sensor; AUC Recirculated; Air Control Sensor (Black box on fan shroud)
Auxiliary Cooling Fan Relay

[X3456]

I have tried everything. I have replaced the fan, the sensors, the fuses, the relays, etc. I even had the ECU diagnosed by SIA Electronics in Illinois and it checked out to be in perfect working condition. What am I missing, what else can I try? I would prefer not to junk the car, but I am at my wits end. The tech at SIA said it may be a software issue, is there another way to have this checked besides bringing it to the dealer? I have already dropped around $1300 into this issue... any help would be greatly appreciated.

This is what I have replaced:
Radiator Fan Assembly
Temperature Sender / Sensor (in lower hose)
Air Temperature Sensor; AUC Recirculated; Air Control Sensor (Black box on fan shroud)
Auxiliary Cooling Fan Relay

What was the complaint at the start?

Sent from my SM-J727T using Tapatalk

[louiemondo]

What was the complaint at the start?

Sent from my SM-J727T using Tapatalk

The aux fan isn't working - it doesn't kick on when overheating or when AC is turned on.

[X3456]

The aux fan isn't working - it doesn't kick on when overheating or when AC is turned on.

This just posted only minutes ago... maybe of some interest to you...
https://www.e46fanatics.com/index.php?posts/18833318

Sent from my SM-J727T using Tapatalk

[Auto Parts Guy]

I would start by using a diagnostic tool such as INPA to manually (electronically) turn on the fan. Of course after you check the fuses and relays and any obvious wiring hacks.
Have you checked that yet?

I thought I had a fan issue too until i realized we have this stupid variable valve ac compressor.. Even though you can see your AC clutch turning, doesnt mean your fan will be on..