Replaced Coolant Level Sensor...Still Broken

[MR2Rocket]

My car kept reading low coolant level on the OBC, so I replaced the sensor when I flushed the coolant today. I crank the car up, and have done so a few more times tonight, and each time I shut off, I get the same freakin error message. (Oh Yeah, I checked the coolant level, it was OK...been doing this for a couple months)

For those who have replaced it, or if you can shed light onthe situation, now what do I do? I checked the connection, and other than a little loose electrical wrap, everything else down there looks OK...

Oy vey

[IronButt II]

Yup... I hate that message!

CHECK COOLANT LEVEL... SEE OWNERS MANUAL!

There isn't much to that sensor... works just like that thing in the toilet tank. Somewhere on this board (or maybe in the Bentley manual) is a test procedure you can do to make sure it's working properly. I'd start there. Just cuz it's new, don't mean it's good.

If the sensor is in good working order, make sure the connectors on the electrical plug are nice and clean. While you're doing that, you can check continuity between the two leads on the plug... make sure they're not shorted together somewhere down in Wirewonderland.

If THAT doesn't get it... then you get to trace the wires. See your Bentley manual wiring diagram, do continuity checks from the connector plug to where ever it is they go.

And if THAAAAT doesn't work... cut a 6" piece of electrical tape and place it over the OBC.

j/k... don't do that. wait for somebody smarter to answer.

[MR2Rocket]

Yup... I hate that message!

CHECK COOLANT LEVEL... SEE OWNERS MANUAL!

There isn't much to that sensor... works just like that thing in the toilet tank. Somewhere on this board (or maybe in the Bentley manual) is a test procedure you can do to make sure it's working properly. I'd start there. Just cuz it's new, don't mean it's good.

If the sensor is in good working order, make sure the connectors on the electrical plug are nice and clean. While you're doing that, you can check continuity between the two leads on the plug... make sure they're not shorted together somewhere down in Wirewonderland.

If THAT doesn't get it... then you get to trace the wires. See your Bentley manual wiring diagram, do continuity checks from the connector plug to where ever it is they go.

And if THAAAAT doesn't work... cut a 6" piece of electrical tape and place it over the OBC.

j/k... don't do that. wait for somebody smarter to answer.

this is going to be fun....

[MR2Rocket]

I Cleaned the connectors, checked the leads, and I'm still getting the message.

I am going to syphon out the coolant from the overflow and check the actual sensor, to see if there is anything obvious wrong with it...it's brand new, I just dont see what could be going wrong.

Is there a reset I need to do on the OBC to clear the Coolant Level Warning? Or is there a fuse for the coolant level sensor that could be bad?

[Jkim]

did you try an obc reset?

[Aradaiel]

Did you bleed the system after you drained it? If you didn't then your coolant IS low.

[yod88]

i got that same message a few months ago...i just added coolant and the message went away after a couple start ups...

only advice i can give is to make sure you have a full resevoir...i didnt, and filled it up till it was full..and that fixed it..

[Aradaiel]

Let the car run with the cap off and the bleeder screw loose. Once you see the stream of coolant coming out of the top hose it's bled. Top it off and you're good to go.

[todor]

I have the exact same problem. I was getting the "check coolant level" message every time I start the engine and every time I turn it off. Then I replaced the coolant level sensor and I stopped getting the message when I start the car, but I still get it when I turn it off...
My coolant level is fine, and I've bled it well. I'm sure the original poster has done the same.

How the hell do you check the wires? they run somewhere wrapped up together with a hundred other wires... for the coolant level sensor, does anyone know where the other end of those wires is? Has anybody ever solved this problem? It seems like tons of people have it, and everyone recommends checking the wires and connectors, but a visual inspection doesn't really tell you much (usually you don't see anything obviously disconnected). so? is this a problem that no one can fix? what would a BMW dealership do if i went to them with this problem (besides charge me a fortune)?

[MR2Rocket]

I have bled the car twice, and I have cleaned the connector, and checked the wires.

The wires just don't seem like the issue for one reason...they bundle up with other wires after about a 1ft. lead, so if they shorted in that bundle, I would expect some other problems.

I don't have Check on startup, but on every shut down after running the car more than 20 seconds I do. I can try to bleed it again...I did read somewhere that if the car sucks coolant down from the reservoir when the car is running, it is too low? But when my car sucks it down, it doesn't go very far. And when the car is cold, the level is right where it should be.

[MR2Rocket]

i got that same message a few months ago...i just added coolant and the message went away after a couple start ups...

only advice i can give is to make sure you have a full resevoir...i didnt, and filled it up till it was full..and that fixed it..

Do you mean full like full to the top of the tank? Or the Kalt marker?

[MR2Rocket]

did you try an obc reset?

How do I do such a thing, kind sir?

[Crazy 13immer]

When there is a solution, this thread should be stickied.

I have this problem and its been driving me crazy. Except I have a wiper fluid low error too. Some people have said that the wires can be crossed between the two, and seeing as how I've recently had my motor replaced, its believable, but I checked and found nothing.

ERRRRRR... NOW I"M RANTING TOO!! DAMN GARBAGE SENSORS!

[MR2Rocket]

It really is ridiculous...although some might argue it makes you a better car owner...having to actually check your coolant yourself. But for me, having a BMW with sensors all over the place was part of the reason I wanted one and not another jap-box.... I wanted the "german engineering" and such...all I have is a german headache.

[devilbones]

Try to startup your car and put the Heat on high. I had to do this, once this is done the coolant level will drop and you can put in the correct amount. Make sure that you bleed the system using the screw near the coolant cover. A complete procedure is listed in the bentley. Good luck.

[MR2Rocket]

Try to startup your car and put the Heat on high. I had to do this, once this is done the coolant level will drop and you can put in the correct amount. Make sure that you bleed the system using the screw near the coolant cover. A complete procedure is listed in the bentley. Good luck.

I've definitely bled it...but I guess I will bleed it a third time! I'll keep trying some things and see if I can get results and post up for the rest of us trying to fix this.

That, and I need a Bentley

[Jeron]

I have the exact same problem. New sensor didn't fix it. It is bled correctly and full. I've changed the coolant twice for other reasons and the problem persists.

If anyone fugues it out I'd love to hear it. Until then it is a minor annoyance.

[99mtres]

I had this same problem and took it to the dealer car was under warranty. Turns out that the cap on my tank was bad. They replaced the cap and havent gotten the message ever since and this was about 5 years ago. I dont know if that will solve you problem but something to look into.

[MR2Rocket]

I had this same problem and took it to the dealer car was under warranty. Turns out that the cap on my tank was bad. They replaced the cap and havent gotten the message ever since and this was about 5 years ago. I dont know if that will solve you problem but something to look into.

A bad cap? Did they offer any explanation as to how they determined that? A cap isn't too expensive, but I guess I'm confused as to how it would affect the level sensor.

[e36m3speed]

I had this same problem and took it to the dealer car was under warranty. Turns out that the cap on my tank was bad. They replaced the cap and havent gotten the message ever since and this was about 5 years ago. I dont know if that will solve you problem but something to look into.

Interesting... i have been having this same problem for about 2 yrs now and i replaced the sensor as well. Sticky this thread for sure when we find a cure.

[MR2Rocket]

Interesting... i have been having this same problem for about 2 yrs now and i replaced the sensor as well. Sticky this thread for sure when we find a cure.

When I'm at the dealer tomorrow, I'll see if they have a new cap on hand...for right now, I'm about to go bleed it again.

I actually have a little more coolant than the "kalt" marker...so I don't know if I should add anymore....

[Daved]

this thread should be stickied.

I just added to the FAQ.

[MR2Rocket]

I just added to the FAQ.

Hopefully one of us can find a solution and make it worth your time

[BCM M3]

I have the same problem...sensor was replaced almost a year ago and I still get the erroneous OBC message.

[yod88]

Do you mean full like full to the top of the tank? Or the Kalt marker?

well i was going for the marker...but i accidentally put past the marker, and "over" filled it...but it was fine