97 E300 diesel trans shift issues with a side order of check engine light
 

Yesterday , my wife and daughter frantically called me stating that the car wouldn't shift from 1st gear and the check engine light came on. When I got home last night, the gear would engage but HARSH. it would slam into reverse and D. Didn't drive it in fear of more damage.

QUESTION:: W210 tranny still operated via vacuum or an electronic transmission control module? ( i did searches with zero result)

I'm assuming that it would be an electronic one because of the check engine light activation. It happened so abruptly that it couldn't be fluid level because there are no leaks as well! Thanks for the help

Your 97 ought to be an electronic 722.6. You can check your vin at mbclub.ru to be certain. If it reports 722.438 its not elec.

Sounds like you are in limp home mode. You can try an OBDII scanner to see what code is showing but usually will need SDS to know for certain whats up.

electronic
 

I was also told by an indy earlier that if my tranny pan has 13mm bolts, it's vacuum controlled and if it has torx screws on it , it's electronic. My thoughts are if the CE light came on, it's electronic. Usually, vacuum leaks via modulator do not keep the transmission on 2nd gear, they just shift harder or harsher, (what ever the right term is)but still goes to all the gears. I'm assuming that it is electronic. I'm going to attach an OBDII reader on it tonight. I think that driving the car with a very deflated tire (almost flat-rear) could have activated the CE light to come on and disabled the TCM thus shooting the transmission into limp home mode. OR the TCM is fried- $600 @ dealership reman! Hopefully the cheaper scenario is the real story.

A very low tire with a greatly different diameter could be an issue with the trans and or traction control amoung others. I think your scanner will give you a very generic code but can not get into the trans computer to see the real codes. Will take a MB quality scanner to see those and clear them; they will still be present and you should remain in limp home mode even if the generic code is cleared wiht your OBDII unit.

Just for the heck of it you should try to reset the shift adaptation. There's a method for doing it involving turning the key on with the pedal depressed and holding it down.

Here's how...see Terry's post #4 and follow it:

http://www.peachparts.com/shopforum/tech-help/177905-w202-shift-pattern-adjustable-dealer.html?highlight=reset+722.6+key+position

I dont think I would do that until the adaptation values were read as they would be reset and lost. That would be valuable data to help determine what trans parameters are beyond spec.

I defer to Terry's judgement on this...have to codes read at the dealer and see what it tells them.

Valuable information guys! I will inflate my deflated tire and see what the OBDII does. If codes are not cleared, I have to crawl my way to the dealership. Thanks,

I'd bet it is the "electrics kit" on the conductor plate inside the tranny which goes haywire on these. Not too expensive...the part is about $200-$250 and labor to install is just a couple of hours. If it turns out to be that you should insist they give you new fluid and filter and drain the torque convertor while they are in there which is now recommended maintenance on them anyway. That will save you the labor of having that job done spearately.

Electrics kit
 

MArty,

How did you know about the "electrics kit"? Did you have the same problem in the past? What code did the scanner give you that indicated this? Could this be a DIY'r ? Thanks for the input

The electronics on some of the early 722.xxx were a problem. IIRC they got fried from fluid leaking into the supposedly sealed unit. I think that was fixed by late 97.

I've seen other posts about similar symptoms caused by this part. It triggers a CEL because the speed sensor is giving bad readings from the electrics kit so the tranny triggers the CEL as some sort of speed sensor code IIRC. Have a look at this one as an example:

http://mbca.cartama.net/showthread.php?t=20780&highlight=transmission

See if your CEL is caused by the same P0700 code.

The 722.6 tranny is probably the only major component I'd leave to the experts at a dealership's service department. I'm not sure if you can DIY it or if the part needs to be coded to the car...but since the fix is not outrageously expensive I'd leave it to them if it were mine.

One caveat...if they immediately tell you that you need a new tranny take your car elsewhere...some dealers only like to sell new transmissions because, I suspect they lack the expertise on site to repair them (and, of course, it is much more profitable).

codes read::
 

OBD II codes as follows:

-PO715 Input/turbine speed sensor A malfunction
-PO720 Output Speed sensor Circuit Malfunction

:confused:

sorry for the bump.... What do I do next?

Any idea how to pin point which had the upgraded o-ring or upgrade that prevented this issue. I know mine was built in February of '97, I would consider it a late '97 MY build...