W202 Radiator fan stuck on + coolant ind

[kerms]

Hi all,

Can someone advise me on what may be causing this problem please. I have a 2000 C220 Cdi Sport(w202) with 85k and the radiator fan is stuck on, it goes off when i turn off the ignition but is on at all other times. At the same time the low coolant level warning light has come on for no reason, as the expansion tank has plenty in it.

I took the car to an indy today and they drew a blank , its booked in with a dealer tomorrow but would like your thoughts on it as well please.

Simon

 

[Hibbo]

Sounds like a dodgy sensor or a loose wire. The fan probably comes on as a failsafe.

 

[kerms]

Cheers Hibbo,,,, Is there an easy way to check your theory ? Where is the sensor ?

 

[television]

You have water in the control box for the fan, there is a mod to the wiring harness to stop this.

Malcolm

 

[kerms]

Television,,, will the dealer engineers pick up on this ?? Is there something I could mention ?

 

[television]

Television,,, will the dealer engineers pick up on this ?? Is there something I could mention ?

Its dead easy to do your self, the little black box is to one side of the Rad,the wires go direct into it from the fan.

Some people dry them out and have been successful, your is not too bad at as it is not staying on when the engine is off.

The only cure is to seal where the wires go in and out then wrap the whole thing in self amalgamating tape.

The cost of the box is £80

Malcolm

 

[kerms]

will that cure the coolant lamp problem as well mate ?

 

[television]

will that cure the coolant lamp problem as well mate ?

I understand that it will, as one of the others had that problem too.

Malcolm

 

[kerms]

checked out the box mate and its bone dry

 

[television]

checked out the box mate and its bone dry

I can only give info from the test results from others on the forum, and this is a listed MB fault including the cure.

if you do a search" 202 fan "you can read the post. the box may be dry now by the heat from the engine. water getting in at some time could still cause the problem.

Malcolm

 

[kerms]

Just got car back from merc dealer and they claim its the 'suction fan ecu' what do you think chaps ??

Do I agree to the £300 bill for this or do I take it elsewhere ??

 

[television]

Is your car a 202193 if it is then open up the fuse relay box to see if there is any water corrosion it is this that causes the the module to blow, if it has.

There is a modified top now for the fuse box

malcolm

 

[kerms]

On my way back from the dealer the fan went off a couple of times, as did the coolant warning lamp. Only to come back on a second later. If this module has blown would it not be permanent and not intermittent ??

 

[television]

On my way back from the dealer the fan went off a couple of times, as did the coolant warning lamp. Only to come back on a second later. If this module has blown would it not be permanent and not intermittent ??

If you want help why not read the post above this

Malcolm

 

[kerms]

ive just had a look inside the fusebox and its bone dry with no signs of corrosion at all. I checked the one in the boot as well, thats dry. I only saw fuses mind you not big chunky ecu's ,, are these somewhere else. my model 202133. thanks for the help malcolm

 

[eric242340]

The control module for the fan is under the front right had side of the bumper (thats looking at the car from the front) and it is open to all weathers. Often the connector gets dirty and a little electrical cleaner does the trick, its worth a try. The module is an alluminium box with fins on it, easy to see.

 

[television]

http://www.detali.ru/cat/oem_mb2.as...GM=717.466&CT=F&cat=44V&SID=54&SGR=045&SGN=03

Mb say that water has got into this box and a modified lid and gaskit is available.

As you say ECUs do not go intermitant, they either work or they do not.

The problem here is that if any moisture gets in it shorts your fan module out to the SAM unit in the same box.

If there is any white powder on the contacts ,that is the problem as the voltage can leak over this when damp, it can be removed by by washing down with lighter fuel

Malcolm

 

[kerms]

ok heres a theory,, ive just moved house and now im parking on a slight slope,, do you think this has had an effect ??

couldnt find that ecu mate

 

[television]

ok heres a theory,, ive just moved house and now im parking on a slight slope,, do you think this has had an effect ??

couldnt find that ecu mate

You will not,you have not got that one,its in the one I put up.

Malcolm

 

[kerms]

malcolm does the rear fusebox in the engine bay just snap open ??