For some reason I keep getting the Coolant Check Level error on my Mercedes.
I have a 2002 c230k. I did a complete flush of the coolant to try and get rid of the error but that did not help. I also changed one of the sensors located underneath and outside of the tank (thought maybe it was a faulty sensor). That did not work either. The coolant tank has the correct level of coolant but the error keeps popping up.
Does anyone know of any solutions to this problem?
The washer fluid is full as well. I just checked that.
However, Now I am getting the Washer fluid level check error and Coolant level check.
I am getting an error for both my washer fluid and coolant level. The washer fluid is completely full. Just like I mentioned in my first post, my coolant was completly flushed out and a new sensor was replaced underneath the coolant reservoir tank.
This was after a coolant flush. Yet the Check Coolant light remained on. After a while the windshield washer fluid light came on. I checked that, and the tank is full. So I am assuming there must be another sensor in the windshield tank and that is definitely bad.
This is probably the sensor that is inside the windshield tank.
Ok, we're using the term "sensor" for two different things. You're talking about the physical sensor that detects the level of the fluids, while I am talking about the sensor that sends the electrical impulse that one of the fluids is low (look to the schematic that someone posted on this thread; they're hooked in series, not parallel, so when one trips up the circuit, the warning goes off, but you don't know which one it actually is).
My guess is that you're barking up the wrong tree, and it's the sending unit for the message, not the physical float in either tank, that needs replacement, as mine did.
So there's a separate message for the windshiled fluid level??? I wonder how the car knows, if both sensors are in series?
Same as many things in modern cars. One wire can carry lots of different signals. Imagine you connect 12V trough 2 switches then to computer. Computer is getting 12V what means everything is OK. Now winshield level goes down what transfer current through resistor in switch and computer is getting 7V what register as low winshield fluid and show you on display. Now there is another lets say higher resistor in coolant level switch and when current pass through that one gives 5V to computer.
Think abouth computer keyboard, USB connector with 4 wires, 2 of them are power and 2 are for data, so how computer recognize all those different keys through only 2 wires.
Yep, I'm very aware of serial communication links in our world (keyboards, USB, SATA, rs-232/422, CAN, I2C, etc. etc.) but didn' think these sensors were that smart. I was thinking they were just simple switches (i.e. open or closed) based on another post suggesting jumpering the sensor plug to determine if it was faulty or not. So these sensors don't 'open' (or 'close') all the way - there's a resistor in them? And you believe the electronics are measuring a voltage or current through the sensors? Or as above, Tommy mentions what I'd call a control unit for sending out 'impulses' (i.e communications) to the sensors?
Here are the pictures. This is only for the coolant level sensor. It is located under the tank. Unplug it than turn the sensor 45 degrees or so and it will come loose.
I did not take pictures of the Windshield washer sensor. But if you remove the "panel" by your tire you gain access to the windshield washer tank. The sensor is located on the right side slightly above the pumps. You will have to pull this sensor out from the tank. So if your tank is full of fluid it will spill all over the place. So be prepared.