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Discussion Starter #1
I was driving my 02 C240 today and while I was driving the car appeared to slip into neutral. I move the gear up to N and back to Drive and it took off fine. The transmission worked fine all day and after the incident. Any ideas?
 

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Discussion Starter #3
No I didn't even think to look. I will see if I can get it to do it again and let you know. HAve any idea what it might be?
 

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Discussion Starter #4
I couldn't get it to do it again but the last short trip to the store it did it twice. I did notice the button with the W S on it was set on W.
 

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Discussion Starter #5
Ok, it happened again today while I was driving. The dash said it was still in drive when it happened. I put it in neutral and then it went into gear but stayed in the same gear. I stopped, turned the car off and started again and it worked fine. What do you think? Thanks for the help!
 

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Sounds to me like it could either be low fluid, or maybe an RPM sensor going bad. You should have to get it diagnosed properly.
 

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Discussion Starter #7
I will take it in. Is there anyway I can add fluid just in case? What kind should I use and where does it go?
 

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Discussion Starter #9
Well hopefully I didn't mess it up. I pulled off the cap for the transmission fluid which seemed to be locked. I poured in some synthetic treatment and about one bottle of fluid. I just drove it into downtown Atlanta and back with no issues. Is there anyway to know if the fluid level is too high or low? Thanks again for the help!
 

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Mercedes-Benz tried really really hard to make it so only certified MB techs can work on their transmissions. That's why they designed their so called "sealed" transmission. The 722.6 (like yours) transmission is kinda a feat to simply check the fluid level. The 722.9 (new 7-speeds) transmissions are damn near impossible to simply check the fluid level, even for a certified MB shop. In your case, you really should have no need to check your transmission fluid level unless you find it leaking. So then, you simply repair the leak and correct the fluid level. A fluid and filter change never hurts. But it's not even an MB recommended maintainance on these newer transmission. But I don't think it's necessarily a bad thing to change it, say every 100k miles or so.

Did you ever check to see if maybe you did have a leak? It would only leak in two ways, really. Externally (with drops on the ground), or through the radiator/transmission cooler. You'd be able to tell if this is the case by popping open the coolant reservior and checking for traces of transmission fluid.
 

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Discussion Starter #11
I would be against changing the transmission fluid myself but don't know where I would drain it. The last scheduled maintenance did show a leak in some seal but they fixed that. Really haven't noticed any leaks as of yet but have not checked the coolant reservoir as of yet. So far since the addition of one bottle of fluid and the conditioner it has been shifting very well. I think it's due for B Service in 3000 miles or so. I will put something under the car and see if there is an external leak tonight. Thanks for the help on the battery drain caused by the power seat module many months ago. I have looked for a replacement yet but it's easy to just plug in and adjust whenever I drive it after my wife.
 

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Discussion Starter #12
It just gets worse! Last night we had a big storm and the transmission slipped once to neutral while still in drive, the alarm kept going off all night and the AM radio reception is horrible. I can't remember what I had done before but not to long ago I had the alarm issue and they replaced something. Is it possible this is all electrical?
 

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Discussion Starter #13
I finally took it into the Mercedes dealer and the radiator had a leak. I guess it's a special radiator for the transmission fluid and it's cost almost $800 to get it repaired. Anyone know where to get a seat control module? What is the actual name for it? Mine is pulling power from the battery when the car if off and needs to be replaced.
 
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