advsub

I have a 2004 s500 and the cooling fon is running on high on a cold start also the outside temp is irratic . The car is driving normal and the temp gauge is normal . Anyone have any idea ,it could help me . I am new to this forum ,first time user

Mike5215

You want to be on the W 220 board, but both conditions are normal for a 220.

wallyp

I would not consider either condition to be normal on a W220.

eldos1

Is the defroster on? That would engage the AC compressor and fan.

tusabes

The most common cause of cooling fan running on high is a damaged ECU, usually from water. Had it rained recently in your area?

advsub

Thanks for all the answers . No I don't have in defrost mode . And I know it is not a normal operation . I am going to a garage to run as an on it ,hopefully this will lead me the source of the problem
Thanks

advsub

There was some rain and I took the Ecu apart and clean it . Ther is one other issue that I did not mention on my previous post . The air condition goes to economy mode even and it is showing a low pressure code (1241 ) after driving for a little while . The out side temp reading is not correct when all this is going on
Thanks for all the help

cybertronicify

There are only a few ways the cooling fan will run at a high rpm.

1) MAX Cool. from the A/C
2) Bad ECU, however this is usually not the case, because the car probably won't start with a bad ECU.
3) A temp sensor, Oil, Coolant, A/C is malfunctioning. Although it may say Normal for the Coolant, maybe another sensor has failed and triggered the fan to spin at a high rpm.

Does the fan return to normal after the engine warms up?

advsub

When the car reach normal condition the fan operate normal . Also understand cold or rain the problem is more apprant . The ac will shutdown with 1241 as a code (low freon pressure ) . With gauge hook up to the ac system the pressure is Normal.

travor121

fan running when engine is cold. reasons and fix. Read Here

Astro14

OK, first, you're resurrecting a thread that is eight years old. Next, the link you provide is not helpful. The cooling fan will go to high to cool the condenser - it is normal. Your link suggests a set of problems, but there are times when this is normal.