oomz82

Hello all

I have a 2013 e class estate auto

The problem i am experiencing is the 7 speed gearbox will only upshift with the paddle shift, downshifts are perfect and smooth

hoping someone can shed some light on what the issue could be

thanks

MJ50

moved to W212 forum...

CaliBenzDriver

That's interesting... your tranny only shifts manually.

Are you familiar how it works?

As soon as you manually interact with paddle shifters, the tranny stops shifting automatically to becomes manual. 100% NORMAL.

Watch couple video or better read owners' manual.

There are couple ways out of manual mode, my favorite is to hold the up shift paddle. You can switch tranny mode by toggling S/M switch.

oomz82

Hi I’ve tried that, I only used the paddle shifters as it was not changing up automatically but still downshifting automatically

Jeedie

Some basics on the 722.9 transmission are in this booklet. Maybe some of the info contained can be of help.

oomz82

Thanks will have a read

CaliBenzDriver

You are saying your tranny simply never shifts gears up automatically not even 2nd or 3rd. It only shifts down. Failures to initially shift up is not caused by paddle interactions.

This is a serious hard fault of the TCU.

Somebody is going to need to scan your tranny to retrieve a list of fault codes.
🤞

oomz82

Do you think the best fix is to replace the TCU

CaliBenzDriver

of course not replace the TCU without knowing why it quit shifting!

Now we can guess it's in limp mode.

The best course is to troubleshoot what your problem is. Tranny is extremely dependent on network partners.

Scan the whole chassis to get more data.
🤞

oomz82

Ok thanks I will get it scanned on Monday and report back with findings thanks for taking your time to help

oomz82

The following fault code has popped up on scanner
U010300

S-Prihadi

Make it a habit to not only to tell of DTC numbers, always provide the description and the brand of scanner being used.
This will speed up assistance by members.

Some scanners may use generic DTC, an MB compatible scanner will use MB DTC, which often the description usually is more accurate. Well they made the car

oomz82

it was Launch x.431

S-Prihadi

Good, Launch for MB is very very good.

ADD : Update your scanner software, that MB software V49.68 is a few generations ago.

oomz82

Do you think the best option is to change tcm and also any idea where it is located
thanks

S-Prihadi

Hang on my man.
Do the simplest one first.
This TCM is powered by Relay R, a mini relay.
There is a TSB on this relay R type, you verify your relay first. There are 3 or 4 of similar mini relay like relay R in my car, in ur car probably the same qty.
I am afraid intermittent low voltage may be an issue , for the TCM from Relay R.


Go and read here the TSB. https://www.tsbsearch.com/Mercedes-B...54-15-P-057373
I do not know why I cant load it here as a PDF. OOps it actually stick-ded hahahah

oomz82

thank you for your valuable input my battery is very weak so I’m thinking to replace that first and see if that has any positive effect if not i will try relays

S-Prihadi

Weak battery can give you problems you can't even imagine.

Also please check the undocumented ground cable under the car I call W-TF is tight and clean and make sure W10 battery ground to suspension strut is clean and tight.
Read here : https://mbworld.org/forums/e-class-w...ital-wire.html

If your location has winter, the diesel glowplug sucks lots of battery power + road salt causing corrosion on the W-TF undocumented ground cable.

Also your alternator wiring is probably is still the YoYo kind low voltage happy, ECO friendly bull-shi-et where your battery is never 100% charged. ECM does not allow it, in the name of greenie.