imcc

I am getting a P0730 Code on my OBD-II Scanner and the car acts like its in limp mode. No forward or reverse gears most of the time and sometimes if I restart it it will work shortly.... Any suggections?

Thanks!

~CL500~

Could be a number of things. Did you recently change the transmission fluid and filter? A faulty transmission wiring harness tends to trigger this code. Did you check the plug adapter O-ring? That has a tendency of failing and causes trans oil to get on the electronics.

Here's from WIS:
Target gear is not reached, transmission in mechanical/hydraulic limp-home mode

• Oil filter not assembled / Assemble oil filter
• Wiring harness damaged, short-circuit, chafing mark / Check wiring harness to ground.
• Shift pressure control solenoid valve (Y3/6y2) blocked (foreign matter) / Replace solenoid valve.
• Control, shift or command valve blocked (foreign matter) / Check slide valve for end position and ease of movement, free off if necessary.

• The spring in the control spool pressure regulating valve may be broken / Replace spring (part no.140 993 58 01).

imcc

Just got the car it was an off lease car I am sure the battery went dead multiple times before it was changed to a new battery i see clear evidence of that, could that have anyting to do with it? I have not checked the wiring to the trans or the o ring. I was planning on doing the trans service tomorrow but in light of this happening I don't want to do it until I figure out the issue. Thanks!

~CL500~

I have never heard of a weak or dead battery causing that particular code to throw.

That would be one of the first things I would do. When you get under there, you'll be in a better position for a diagnosis. The biggest thing is to check for evidence of leaks. Good luck

imcc

Thanks appreciate it! The harness Plug adapter o ring for the harness I assume is inside the trans and should be obvious when I change the filter / fluid? Also for good measure should I just replace the shift pressure control solenoid valve? They appear to be like $23.00 From worldpac?

imcc

Thank you for all the Help CL500! Unplugged the Trans harness connector and out came trans fluid!!! Ordered a new Grommet / O ring and doing a trans service now and I will let you know!!! Bingo you hit it on the head I think!!! Thanks again and I will keep you all Posted!

~CL500~

NP man.

I was gonna say to check the plug for fluid before doing anything with the solenoid valve, but it looks like you may have found the problem already. Make sure you clean the electronic connector well. Here's a good reference for you with pictures courtesy of mleskovar and sunman. It's on a C-Class, but it's a 722.6 trans.

http://www.installuniversity.com/mb/...ans_oring.html

Let us know how it goes.

imcc

Thanks for the info! Imissed the 7 mm captive socket bolt and broke the electronics board which I replaced today, Oh well, anyway now since I installed a new electronics board I must have it re recognized by the ecu which means a trip to the stealer... But hopefully all will be well. Thanks again and I will let you know the outcome!

~CL500~

Ouch! All worth it though. Nothing like bonding with your car.

imcc

Well still issues doesn't appear the electronics board needed coded, Trans pressure seems ok, but stuck in basically neutral now. After new electronics kit and harness orings, basically I went from ocasionally having trans to nothing other than park and neutral... Any ideas? Thanks!

~CL500~

That sucks. The repair you did was necessary anyway because it was leaking. Don't feel too bad about it.

At this point, I would get the car hooked up to Star Diagnostics and verify codes in the tranny. It would be worth the $$ as you did all you can do. The code you received is only OBD, not the hidden Benz codes.

My first post above lists some possibilities. Now you have to pin point exactly where the problem is. Get it hooked up to star and hang in there. Good luck!

imcc

I replaced the whole valve body. Based on star diagnostics pressure solenoids not responding... Trans worked great for 50 miles and went out 2 miles from my house luckily not further on the way down to Florida where I am now. I am having a flat bed pick it up and tow it to the dealer. I am guessing either it went out again which would be weird but possible or there is another issue making it act identically...

m4xm1l10n

that code is usually THE MASS AIR FLOW SENSOR

ctravis595

Can anybody else attest to this p0730 being related to the maf? Seems completely unrelated in my opinion

enrikerace

Bump, any update? im experiencing the same issues... did you solved it?

ibeforreal

Enrikerace, watch all 6 of this guy's videos. They are very good and may explain your problem.

E320driver

Similar problem.......
On my 1998 E320, I had a retired MB mechanic replace my conductor plate, filter, and electrical connector with the o-rings after cleaning my shifter module didn't get it out of limp mode. Now, the "incorrect gear ratio" code is popping up. Any ideas from the MB buffs/experts here?

Rick_in_Denver

I have a "new to me" 2007 S550 4matic that is showing the same code (according to an auto parts store) and is slipping intermittently (step on gas... vroom, no go, then slow go... other times, go go go). Anyone else fix this? It is also showing a P0717 Turbine/Input Shaft Speed Sensor Circuit No Signal code.

Thanks! Bummed...

tusabes

check your tcu computer in the engine compartment to see it there is oil leaking into it

the most common issue is there's an electrical connector that leaks and let's fluid up into the tcu causing these issues

see the first video here
https://mbworld.org/forums/s-class-w220/608957-w220-how-repair-videos.html

Rick_in_Denver

Dealer is saying it is a $1,500 transmission plate...

tusabes

you can get a conductor plate on eBay for $100-200 and an independent mechanic can install it for a couple hundred bucks

a dealer will overprice everything

iamrclose

Had these codes on 2004 E320 had the Star verify and recommended replacing Conductor plate and filter. While they had it out I went ahead and replaced the solenoids. After all parts replaced car runs fine with new fluid. The conductor plate came with the plugs everything done for under $500 parts and labor.

FlyHigh985

Did you buy oem part or aftermarket i replaced my conductor plate and filter it didn't help they were after marker car still did the same thing. I'm wondering should i buy a oem conductor plate or just some new solenoids please help

tusabes

iamrclose

My parts came from Ebay so not everything was OEM but compatible. The solenoids were remanufactured OEM. I went ahead and replaced the solenoids since they are ob the conductor plate. What codes were are you getting? I'm not sure if I can post the link but will try. Prior to replacing these parts, I had replaced the shifter as it will throw codes as well. I am a DYI as long as it not under the car (safety first) so did a lot of the work myself.

Transmission Conductor Plate+Connector+Filter+Gasket KIT FOR Mercedes Benz 722.6


6pcs OEM 722.6 Solenoids Set for Mercedes Benz 5-SPEED Automatic Transmission