Low Coolant Sensor Question

[shertex]

A friend of ours has a late model E class wagon...I think it may be 2011. She texted me about getting a low coolant message. Since she was in the area I told her to stop by so I could take a look.

The reservoir seemed fairly full. But when I removed the cap I noticed that the level was just below the top of the two electrical prongs in the reservoir. Am I correct to assume that coolant needs to cover completely those two prongs in order for the sensor not to be tripped?

Thanks.

[Ferdman]

shertex, on the typical coolant expansion tank there is a "full" line. With a cold engine the coolant should be at that level.

[shertex]

Originally Posted by Ferdman

shertex, on the typical coolant expansion tank there is a "full" line. With a cold engine the coolant should be at that level.

Yes, I know. I'm asking about the sensor. I only had the opportunity to look at the coolant level when it was hot.

[Ferdman]

shertex, I am unfamiliar with the specifics of any MB vehicles after 1998. Our older E-Class vehicles have a float switch in the coolant expansion tank that initiates a warning light for low coolant level. Based on your description, I would think the coolant level needs to be above the electrical prongs to avoid the "low coolant" warning message.