BeaverMjr

My car, a c230 coupe, started announcing a malfunction: Check Coolant Level. I did and it was fine. The messages were sporatic and seemed to have no rime or reason. I watched for a leak and didn't see one. Today I dropped the car off at the dealer. The service dept told me that the malfunction was due to the windshield washer fluid being low and something about the 2 fluid systems sharing the some components. They topped off the fluids and told me to pick up the car after work.

Does this make sense? why would the car not report low washer fluid? Does this sound like I'll be returning to the dealer for the same problem?

Michael

nlpamg

I had the same exact problem. The sensors are on the same circuit so when the windshield washer is low, it triggers the coolant.

I still took it in and my dealer topped off the windshield washer fluid and the message went away...

drexappeal

Same thing happened to me, Michael.

It seems that they share the same sensor, so if one shows up as a malfunction, the other might possibly. Thing is, I've had low washer fluid before and that didn't cause both malfunctions to show up, but when my coolant was low, I refilled that (1/2 and 1/2 of course), the malfunction went away temporarily and came back intermitently (along with the washer fluid). I was puzzled and brought the car in on an "emergency" visit (without an appointment). They pulled the car away and came back 5 minutes later telling me about the sensor and they topped off both reservoirs. Since the washer fluid was low also (and I didn't refill that, since there's some special solution MB supposedly has), it kept the coolant malfunction going whenever it indicated the washer fluid.

I haven't had any problems since.

drex

r_liebo

I've heard of others with the same issue as well -- dealer is correct here. Part of MB poorly thought out electronic diagnostic system setup (such as your car telling you that low fuel level is somehow a "malfunction" that needs fixing). Hoepfully in the future MB's diagnostics won't post such dire warnings for such innocuous issues.

BeaverMjr

who ever thought up that diagnostic system should have their head examined. How am I supposed to know that low coolant means low washer fluid? What other situations can I receive a message like this?

drexappeal

I thought the same thing too. Very poorly put together as far as a diagnostic system is concerned, however, since we have no alternative, at least both reservoirs are easy to access, so you can check which reservoir is low without needing to bring it in to the dealership.

BeaverMjr

Now that I know the 2 are monitored be the same sensor, I will do that.

HoustonC230

I had the same issue, and the replaced it as a faulty sensor. After reading above it looks like they were just after the warranty $.

mleskovar

[QUOTE= at least both reservoirs are easy to access, so you can check which reservoir is low without needing to bring it in to the dealership.[/QUOTE]

How do you check the washer fluid reservoir level? The way it's set up you can only see when the level is up in the the filler neck. Can't believe they have a fluid reservoir that you can only tell if it's beyond full ...or am I missing something?

drexappeal

Unless the 320/240's are different than mine, you should be able to wipe down the reservoir and see how high the liquid is to the top. Since the 240 and 320 are bigger engines, I'm not sure if the washer fluid reservoir is located in a different spot.

Can anybody confirm if it's in the same location or not?

mleskovar

Same location....all you see is a small area around the top of the resevoir....3.2 qts. without headlight washers and 6.4 qts. with them. Doesn't bother me because I rarely use the windshield washing feature. But for those that do... you can't tell how low you are. Poor design.

kokketiel

I wouldn't worry about it too much. We had the same problem (low coolant light) in a SLK230 Kompressor (different car, but same engine). I added a cup of water to the radiator, and we never had the problem again.