Was driving home and noticed the cooling fan running non stop for the duration. Parked and turned car off. Started her up again and cooling fan on immediatley started for the rest of the drive home. I I have an 05 roadster and did a search with no real answer. Checked coolant and oil and no problems there and no engine light. Could the issue be associated with a recall. Not sure as a vin search showed nothing for my vehicle. Any ideas? There's after market warranty on the vehicle but if this is something I could fix I would gladly do it. Will not go to the dealer ever....ever. I will say no more. Thanks for any help.

 

Fan module most probably, driver side front fender, metallic silver box. Replace it, not cheap really so get your warranty card out.

 

Going to check the warranty tomorrow. Approx. how expensive? I know a steering dampener quoted, local dealer $840 when the same part from the states cost $19.95.
Hope she's covered.. Thanks from Brampton

 

This is the part. $200
MERCEDES E C CLK S AUXILIARY FAN CONTROL RELAY MODULE | eBay
It could also be the temperature sensing unit in the radiator that is broken.
The fan control module often fails though. Tough call, the dealer will possibly change everything until he gets it right and charge you an arm and a leg.

 

Was the A/C on?

 

No the a/c was not on. It's still rather cool here. I checked with the dealer and they said the module was covered through a TSB. I take the vehicle to the dealer tomorrow so I will keep you posted. The part's ordered from the states will take 3-5 days. I hope the motor doesn't burn out by then. Thanks for the amazing help again. Knowledge is power!

 

Ok here's what the tech at the dealership told me after 2 1\2 hours hooked to a scan tool. The vehicle has a fault/ground somewhere possibly at the hvac controls and that it could not be the fan control module because the fan cycles from high to low and then stops and starts up again and the module only controls the fan to start and stop. This may be a ploy to get me to pay for another part, who knows. Another tech told me it could be the pcm but that seems unlikely. Is there a way to test the fan control module without installing it to another crossfire? It's my understanding when the fan speeds up, its caused by the alternator kicking in. Is this true? Need help please and appologise for not being clearer on the fan cycling.

 

Took the crossfire to another dealer today and there seems to be a short somewhere causing the radiator fan to operate eratically. The tech says he thinks it could be caused by a faulty A/C pressure switch. The racall for e-19 cooling fan and module already performed a couple years earlier so scratch that idea. Wiil find out today if part fixes the problem. X fingures. Keep everyone posted.

 

more then likely it could be a faulty fan controller. I went through a similar issue, but both my fan and my controller were toast.

 

Good to know, sorry to hear. The dealers looking at the fan control module too finally. I WANT MY CAR BACK

 

Update: Dealer replaced "Fan control module" and fan still on. 80 degrees here but temp gauge is normal just below half. Could someone asnswer for me what is normal running time for the cooling fan on a warm day? My understanding is the fan would only run when temp gets to high displayed on the temp gauge(at or above half). When I drove home from the dealer, the fan was on 50% of the commute. I take the car back tomorrow.

 

Ok. another update. The dealer found a fault and traced it to a a/c pressure switch and replaced it along with the FCM. The fan no longer runs all the time...progress. However the problem is this. When the fans on, it runs at the highest speed and is very loud
and anoying. Does the fan always run at one speed?(high) and should it not blend in with the sound of the engine? It's almost embarassing when stoped at a light. I have had no access to another crossfire to compare making this problem extremly difficult. 2 months and counting....

 

The fan runs as slow speed when the A/C is on, and will run at high (or at least HIGHER) speed if the engine gets too warm. The needle will be just past halfway when the engine is getting "too hot".

Also:

1) The FCM, under command of the ECM, is a variable speed controller. But it's the ECM that tells the FCM what speed to run. Running at slow speed when the A/C is on is a default, to insure that SOME air is moving over the condenser when the car is stopped.

2) A faulty sensor telling the ECM that the motor is too hot will make the fan run at high speed.

ALSO, if communication breaks down between the ECM and FCM, the fan will run in "emergency mode" which is high speed. When the communication breaks down, the ECM will also see the breakdown and light the light on the left side of the dash - it looks like a radiator.

If you have no light, this would indicate that communication between the FCM and ECM is probably ok AND that the FCM is likely ok (since the ECM is "talking" to the ECM enough so that the ECM is not lighting the fault light.) I'd lean towards the problem being a bad temperature sensor or bad ECM itself - especially since you indicated the FCM has been replaced.



I hope this information helps.

 

wow. great info. I will let the tech at the dealer know tomorrow and be done with this issue once and for all. Thanks Pizza Guy

 

Just curious what a ECM and temp sensor cost? Anyone know? Can't be cheap because a ECM rebuild costs $293.