I'm trying to fix the cooling fan on my 02 CL55 Kompressor as it doesn't come on. I bought a Foxwell NT530 to help me with the various faults which the car has. The most serious is the fan not working (my a/c is also doesn't work).

Using the Foxwell I can activate the fan from 10% to 100%, but only with the ignition on, not the engine running.

My queston is this - does the Foxwell generate the command for the fan to work, or does it tell the ECU to generate the command?

If the latter, then I can rule out the ECU as being the problem...which I very much hope is the case!

Many thanks

 

You should seriously consider a membership with @BenzNinja with your coding and diagnostic issues. Seems he has a pretty good promotion going right now.

https://mbworld.org/forums/mercedes-...more-free.html

 

I’d rather you just answer my question 🤮

 

That was rather snarky. Good luck getting help here with that attitude. Maybe call Foxwell and ask them.

 

OBDII scanners communicate with the ECU. If you can activate the fan via the scanner, it would seem that the problem is on the ECU's input side -- the switch or sensor that tells the ECU to activate the fan. Any fault codes?

 

Thanks, really helpful replies. Yes contacting Foxwell is a good idea. Either the ECU is not processing the signal from the temperature sensor or the temperature sensor signal is not getting to the ECU, though the temperature gauge works fine.

 

 

Many thanks and sorry for the narky comment. I read on an SLK forum that the temperature sensor can show the right temperature on the instrument cluster, but not activate the fan.

Unfortunately the sensor is not easy to swap on the m113k engine.

According to this diagram it’s not the ECU which triggers the fan, but the ME? Mine has an integrated fan controller on the fan - is this the ME?

 

BenzNinja's post is a good reminder of how complicated and intertwined all the systems comprising a contemporary automobile are. I expect my Homelink door opener will someday malfunction due to 2 psi low pressure in my left rear tire (lol).

 

ME and ECU are one in the same. ME=ECU=N3/10.