cg_06c230

2006 C230, 55K miles
7 speed driver adaptive automatic transmission with manual option

3 times in the last few weeks I have had an issue where on normal acceleration from a stop the car would not automatically shift up from first. No luck with forcing it by using the manual option. Each time I immediately pulled over and restarted the car which resolved the issue. There were no weird transmission sounds or any sign of issue. Anyone else experience this? Could it be a computer glitch since the restart seems to resolve it?

Glyn M Ruck

The car is going into limp mode. It resets when you reboot by restarting. Get hold of an OBDII scanner & check for codes. Check tranny fluid level - not easy with a 7G - no dipstick tube.

cg_06c230

Thanks for the info. I scheduled a service appointment to get it checked tomorrow. I’ll let you know how it goes.

cg_06c230

You were correct about the car being in limp mode…the cause according to the service department is a transmission valve sensor that without the warranty would have been $3,000.00 to fix…that’s no decimal error, they said 3K! I was shocked at the cost. Anyway, the part is on order and they will install next week.

samaritrey

i would love the pn when you get it back i want to see this part lol 3k i would sell my car if i needed one.

Glyn M Ruck

Valve body & electrohydraulic unit problems can be damn expensive to fix. This is why I encourage people to service their transmissions.

johnand

+1. The 7G is outrageously expensive to replace. The TCU and valve body are considered 1 unit to MB. If there is any issues within the valve body, they replace the entire valve body assembly.

Just curious to hear from the OP. Did you have your transmission serviced before this incident?

johnand

Current valve body assembly is $1250 MSRP. Add labor and parts for fluid and filter change which would go along with that, and you are not too far off.

JoeVal

From what johnand posts in the 3-grand, there are $1,750 in other parts and labor. If you wish your ATF and filter changed, they probably will charge you for materials and extra labor. Ask before hand to make sure you go in knowing what's coming, and they know what they should do.

cg_06c230

I’ve had all of the recommended services on schedule with the dealer I purchased from. The transmission service was done in December 2009 at 47K miles. The car is in like new condition. I hadn’t had any issues til this.

Once the parts come in and the service is done I will post all of the details. I have asked them to replace the fluid and filter as well which they said will cost me $150…no complaint on that since my cost could have been $3150.

LILBENZ230

A transmission failure at 55k miles? Unacceptable. Did Honda build this transmission or something?

A car that can't make it more than that many miles without needed $3000 in repair costs is not a car worth owning. Mercedes has offered you nothing in the way of goodwill? I must say in your shoes I'd get rid of it ASAP and never look at Benz again.

Glyn M Ruck

Mercedes fixed it under warranty!

LILBENZ230

Yep.. I shouldn't be posting with so little sleep.. I missed that entirely. I was reading that "his cost" was $3150 instead of his cost could be that.

cg_06c230

I have to admit, if the repair wasn’t being done under warranty I’m sure my feelings would be different on this. Since it is all being taken care of though, I’ll just shake my head in surprise at the cost and count myself lucky it didn’t happen at a higher mileage. The parts are supposed to be in on 8/12 so I’ll hopefully have the work done that day or the next. As mentioned, I’ll post the detail from the work order.

Gynecologist MD

Ford* Perhaps known most for their trans to give out before 100k?

LILBENZ230

No that title would definitely go to Honda.

Glyn M Ruck

Benz have fixed the 7G valve body glitches - You should be good to go for the life of the car - Keep up servicing every 39,000 miles.

EDIT - make sure your car has the latest 7G software flash.

benzmodz

Really ? I have a dipstick for it.

benzmodz

In 722.9 transmissions there is a speed sensor that wears out in the valve body. Once it goes offline the valve body stops working.

johnand

Pics or ban Unless you have some strange one off 722.9 transmission, which I doubt, no 722.9 transmissions have a dipstick tube. They have a standoff pipe in the transmission pan and level is checked at correct temperature allowing excess fluid to drain out the standoff pipe.

pcy

May be someone (either the previous owner or a technician who worked on your car) forgot and left the trans fluid measuring dipstick in the trans filler tube. May be they lost the dipstick cover and the lock pin ...

Glyn M Ruck

Those items are for a 722.6 5 speed auto dipstick tube!!!!

cg_06c230

The parts came in early and the work was done today. The work order is a bit hard to decipher but here are the main items: Electrohydraulic control unit for 722.9, transmission turbine speed sensor, transmission valve body, and misc gaskets.

It drove fine on the way out; I had to go about 30 miles on the highway to get home. The shift timing felt different but they mentioned I could expect that since the transmission needed to re-learn my style(?)… anyway, here’s hoping nothing else goes bad since the warranty is officially up shortly.

Thanks all for sticking with me on this.

benzmodz

I can always send the tool back .... I didn't open it yet. Maybe he sent me 2 722.6 tools.

I spoke to a real expert and he said the forum was right.

Glyn M Ruck

Those are the bit's I would have expected. You should be good to go for a long while yet.

The tranny is auto learning so it will have to re learn your driving preferences. If it has the new flash you will get used to some subtle new changes in behaviour that are permanent. Johnand might wish to expand on this. He is accustomed to a 7G in everyday driving & can explain the new changedown program when running up to a stop etc better than I can. He has been through the various generations of improved software for the 7G.

Good luck