mdss

Hi wondering anyone can help..... I hope so!

I have a clk55 amg 2003 the cars cooling fan is running constantly as soon as the ignition is turned on and whilst the engine is on also.
It runs at maximum rpm I think its in safe mode.

I have had the car at a few garages and first I was told that the fan control unit was faulty so after I was relieved of over £400.00 I was then told it was not this.
The car has been plugged into DAS/AUTOLOGIC/EXESTRA(probably spelt the last one wrong lol

All the diagnostics show no fault codes and I have now been told that the ECU is at fault.

I was wondering if anyone else has seen this problem and if so what was the solution?
Can the ECU be sent away and if so to whom in the UK?


In this thread from this site I read there is a wiring harness that was issued in a service bulletin do you think this looks like a likely fix?
https://mbworld.org/forums/c-class-w...orkshop-2.html

sorry for all the questions!
The car has been fantastic for over 3 years with no problem and now its like "the never ending story"

Thanks in advance for any help it is much appreciated.

HCUBED

If the mechanic told you the fan control unit was bad, and he was wrong, why not try to get your 400 quid back? Seems like he shagged you.

betrezra

there is a pretty good thread I read on here somewhere...... about this very issue.
I recall it being an expensive wiring harness and/or control module or both.

Someone rigged up a cheap summit racing fan control unit as a fix.... if I were keeping the car I would just suck it up and get it done right..... with MB parts...... try to get a true diag from a dealer......... then if you don't like the price..... just pay for the diag... and DIY.

Will save you from parts swapping.

GL.

mdss

Hi just an update

betrezra suggested the wiring harness and control unit, well i did both and it has not worked i checked the wiring in the SAM and swapped the relays around but still no joy.

To be honest i am completely confused as is every technician.

Could it be the ecu??
any help is appreciated

betrezra

Have you run DAS STAR?

mdss

hi yes I have run star etc and still no one can figure this out very frustrating.

Tata55

I m a 32 yr old female never touched a car be fore now!!! I m proud never the less I m kinda going thru same issues
I feel like my car is hot cooking I have a heat gun it says it's not but it gets so hot to the touch so fast where I ve owned the car three years and it's never had this problem until real recently my cats where the first thing to go out it's gone down from there any how my thoughts are egr valve possible sensor temp or aux water pump possible clog in your system I would change all cooling system and have your whole ac and heat system diagnosed and never trust the ppl at dealerships they are no smarter than you or I hands on exp is all they have on me and proceeders execution abc 123 I trust ppl here more so than anywhere we love our cars