Coolant light on dash

[delb0y]

Hi folks
I have a w211, 320 cdi, 2007
Coolant low warning light issue, both sensors replaced on in the block and coolant tank, been told it could be a wiring issue..

If anyone can advise will be great
Thanks

 

[Trickythemerc]

Other than checking what you can see visually a scan may show an open circuit somewhere, indicating a broken wire in a loom ?

 

[Ted]

Istr that for some reason some earlier Mercedes had the washer fluid light wired into the same circuit.
Could be worth checking out.

 

[PolishGeorge85]

Is this warning on all the time or just when you switch ignition on?

 

[Uky]

Some car manufacturers specify de-ionized water to be used
when mixing anti-freeze for the -40C or so lower temp requirement.

If the level sensor uses electrical conductivity, de-ionized ater
will not conduct the (very small) currents needed not to set the alarm.

Mercedes does specify that tap water is OK to use.

 

[delb0y]

Warning is on all the time, thanks for the reply guys, will have a look into it, I may drain the water in the expansion tank and add deionised water with coolant, other than that most likely a wiring issue,