Limp mode with P0715 and P0730 codes
 

Hello all! I have a 2004 c230 with 256,000 and it’s currently stuck on limp mode.i was leaving the gym and it just started driving weird and then would not accelerate. I can’t even go above 10 mph. I have the error codes P0715 and P0730. I’ve been looking online and noticed that it could be the transmission valve body. I have all the stuff saved to replace everything myself as I try to work on my own car when i can. Has anyone else has this happen or can provide any advice on how easy (or hard) it was to fix. I’m hoping this is the issue and once it’s fixed i can drive it again. Also i saw a lot about resetting the TCM. I see videos saying you can do it by pressing the gas and etc if you don’t have the reset tool. IS that true? If there are any special tools I need, feel free to share.

You need to pull up the passenger side carpet and floor board and check the TCM for ATF contamination. You will also need a scan tool that can read codes from the and reset the TCM.

once i do this will i still need to replace the conductor plate?

There's no way of knowing until you pull the stored codes from the TCM. Limp home mode simply means the TCM detected a problem and it's trying to protect the transmission from any further damage.

The easiest cheapest thing to do right now is to pull up the carpet and check the TCM for ATF contamination and borrow, steal or buy a scan tool that will talk to the TCM. The cheapest option are icarsoft i980, icarsoft MB2 or foxwell NT520. Good luck.

so the P0715 and the P0730 don’t mean anything. I went to oriellys and had them read the check engine light and these are the codes it gave.

They are both generic OBD2 engine trouble codes telling you there's a problem with the transmission. Without communicating with the transmission directly there's no way of knowing exactly what's going on. And at the very least you'll need to reset the TCM with an MB specific scan tool.

im going to start there. Going to check out scanners now. Once i get the scanner, how to i connect it to the TCM?

It plugs into the regular OBD2 port under the dashboard. Check out some to YouTube tutorials for icarsoft.

thanks. I’ll update once i get the scanner and see what codes and the condition of the TCM.

https://cimg9.ibsrv.net/gimg/www.mbw...48130c467f.png

is this the correct icarsoft scanner. It’s the icarsoft MBII. I want to make sure before i purchase on amazon.

Yes, MBII or i980 will do the same job. i980 is more compact and cheaper. I keep the i980 in the glove box.

Ok so i got the i980 scanner and it gave me these 2 codes:

P2502- the gear is implausible or the transmission is slipping

P220A - the speed comparison of Y3/6n2 to Y3/6n3 is implausible.

What should i do now?

Check the TCM for ATF contamination. If none is found replace the conductor plate, plug and filter. You could also just clear the code and see if it comes out of limp home mode.

will do. I’ll check it out right now.

I should probably add a bit more detail. There's an input and output speed sensor built into the conductor plate. This is a known failure point in the conductor plate. The only real solution is to replace it. There's also the remote possibility that your clutch packs are failed in the whole transmission is garbage. That's very very unlikely unless you got coolant into the transmission or something like that. The most likely failure is the conductor plate. It's also possible that you can temporarily get it out of limp home mode and keep driving the car until you get a new conductor plate. But it might end up in limp home mode at any time randomly.

More info
https://www.benzworld.org/forums/w14...topics/2312402

Ok. Clear the codes in the TCM and try a test drive around the block.

Even without changing the connector plate?

Yup, it could be an intermittent fault at this point but the car stays in limp home mode until you clear it. Worst thing that could happen is that it goes back to limp home mode. You'll have to replace the conductor plate but at least you have use of the car until then. Keep the i980 in the car.

shifts and works great! Omg you are a lifesaver!! I appreciate your help sooo much. I’ll be ordering the connector plate from amazon this week. And I’ll work ok it. Should i replace the solenoids as well?

also the check engine light stays on. Will that go off when it is fixed?

When it's NOT in limp home mode do you have a hard 1-2 shift? If you do I would also replace the lock up torque converter solenoid. This transmission locks the torque converter in every gear which is kind of unusual so the lock up torque converter solenoid (TCC) wears out much faster than the other 5 solenoids. Even if you don't have that problem I would still consider replacing it. It's $28 on eBay. The other solenoids should be fine.

The CEL is still on because the engine computer is storying it's error codes separately. On the icarsoft you'll have to go into the engine computer menu (ME2.8 I think) and clear codes there.

When you get the conductor plate on Amazon read reviews careful. Some no name brand Chinese conductor plates are poor quality. I used the Beck Arnley conductor plate which was a reboxed genuine Mercedes part.

The cheapest synthetic ATF designed for this transmission is Valvoline Maxlife. Look for "Mercedes NAG1" on the back label.

You'll also need a 722.6 transmission dip stick which can also be found on Amazon or ebay for less than $20.

Make sure to have torx sockets on hand. This project is totally doable at home by the average DIYer. You'll find some really good tutorials on YouTube. This transmission was common on Mercedes, Porsches, Jaguars and millions if Chrysler's over the span of almost 20 years so parts are cheap and plentiful with a lot of info available.

Here's some pics the same job on my E320. I had to split the valve body in order to install the Sonnax kit but I don't think you'll have to do that.
https://imgur.com/a/8X4RT75

Overview video.

thanks so much for the info. I ordered the TCC off eBay and i will Fox it just to knock it out. Waiting on all the parts to arrive so that i can do the work.

Transmission fixed!
 

I want to thank everyone for helping me with this!! All your knowledge helped me fix my issue myself and save $1000s. Once i turned the car on after putting it together, the check engine light cleared it self.

tjts1: which of the 6 solenoid is the TCC solenoid? After replacing the conductor plate my tranny still has a 1-2 hard shift. Can you post the last picture in your link (conductor plate with solenoid assembly) here with the TCC solenoid circled for us?