Engine Coolant light on dashboard

[tcmtrailerboy]

Hi,

I have a ml 270 1999 and the engine coolant light is permanently on, this happens after about 30seconds from a cold start and then continues whilst driving. The fluid seems to be at the correct level - I have read before about cleaning various sensors but not sure if this is relevant to my problem, also not sure where these are located if this is a likely solution?

Thanks

 

[grober]

Sounds as if your coolant level sensor is faulty. Cant tell you exactly where that is but this might help. http://www.detali.ru/cat/oem_mb2.as...GM=717.461&CT=F&cat=04S&SID=50&SGR=165&SGN=02
the other possibility is the coolant temperature gauge which is normallymounted on the thermostat housing. http://www.detali.ru/cat/oem_mb2.as...GM=716.644&CT=M&cat=21T&SID=20&SGR=015&SGN=01

 

[Diesel Benz]

How about your windscreen washer indicator, is it also on? The two sensors usually are connected to the same wire (resistor coded).

 

[tcmtrailerboy]

Thanks for your replies,

I will check both links out to see if i can identify a fault -

I am unsure of the washer sensor, as I dont think my model has it fitted still worth looking into though.

Cheers

 

[Diesel Benz]

Thanks for your replies,

I will check both links out to see if i can identify a fault -

I am unsure of the washer sensor, as I dont think my model has it fitted still worth looking into though.

Cheers

There seem to be several different options, depending on the model year. Some do not seem to have washer level indicator at all (strange to me). The coolant level switch also seems to be a conductivity type of a sensor (AC sensor), if I read the diagram right. This may be sensitive for cable and connector leakage.

But none of the ML options seem to have combined wiring for the wind shield washer level indicator, the issue should then be at the coolant level sensor, wiring or instrument cluster.

Are you able to remove the sensor? Perhaps the electrodes have "disappeared".

Edited: I realised you actually mentioned the MY of your ML. A 1999 car should have a "normal" level sensor switch. There is a parallel resistor but you could measure the sensor resistance (unplug the wire) and it should show short circuit or the parallel resistor (don't know the resistor value). Should also be safe to short circuit the wire pair when unplugged, the indicator should go on and off accordingly.

 

[szamac]

Hi, there.

i have a problem with my clk 200 97 sport coupe.
My two indicators are somethimes on, coolant level indicator and screen wash liquid.

somethimes they are gone, i dont know what i should do.

I checked earth wire but still is same.

please give me some advice !

 

[kole301]

Did you check the coolant level and the level of the screen wash liquid..?

 

[szamac]

yes, i checked.

That was silly question.

 

[Diesel Benz]

yes, i checked.

That was silly question.

Have you checked the washer level switch? It could be one or the other (coolant or washer level switch) but I think the washer goes more often (did I remember right?) and once one of the two fails, both lights come on.