S211; Gear; Impossible to shift from D to R (and P)

[Oddih]

Have a S211, E320 CDI, 2006.
Symptoms:
Shifting from P to R (and D) goes just fine.
Shifting back from D to R (and P) is impossible.
Two ways to go back to R (and P) from D:

1. Shift to N - turn off the engine - then R (and P)
2. Shift to N - engage parking break - let lose brake pedal - then R (and P)

No error message in display.
Could it be a sensor failure, leading the car to believe that the car speed is not zero?
Then this sensor is overridden when the engine is stopped, or the park break is engaged?
Other causes?

 

[Cole@MBS]

You need a new gear selector, it’s a very common fault with the 211 and 203/209! About £450 from merc and normally on back order, you can fit a 2nd unit if you can find one!

 

[alexanderfoti]

You need a new gear selector, it’s a very common fault with the 211 and 203/209! About £450 from merc and normally on back order, you can fit a 2nd unit if you can find one!

As above, do lots of them

 

[Jim2]

You need a new gear selector, it’s a very common fault with the 211 and 203/209! About £450 from merc and normally on back order, you can fit a 2nd unit if you can find one!

So is this problem caused by a "mechanical" fault, as opposed to electrical? iE: physical wear and tear on the movable parts of the selector?

 

[alexanderfoti]

No it's electrical. The lever looses rhe ability to determine the it's location.

 

[Oddih]

Thank you very much for the replies. Since last time I've done some checking using a iCarsoft MB V2.0 that I just bought. Firstly, regarding item two in my original post, you don't have to "engage parking brake", just let lose the brake pedal.

Below you see the output from the diagnostic tool:



After identifying the error code I could google it, and found (among many other) this one:https://forums.mbclub.co.uk/threads...n-detection-has-failed-w211-e220-2004.242177/. He seemed to manage to fix the problem, although perhaps with a bit of luck.

There are a few more issues:

1. How do I know that it is the "gear selector" and not the electronic module that has failed?
2. Sometimes it works, but most often not. Could it be any hope of repairing if it's just a bad connection?

 

[alexanderfoti]

1. The gear selector is the electronic module. The selector lever detection happens inside the ESM. Its implemented differently on different models. You can try and take it apart and clean the contacts.
2. yes as above.

 

[Oddih]

Thank you again. After taking a closer look at the error codes (which I finally managed to import to Excel to get a better overview), I found another error that could be linked to this one. The text in the last parenthesis mentions "ESM" as one possible cause. Moreover, it points to a control module N15/5:



Searching for C404, I found this link: https://www.troublecodes.net/ucodes/u0404/

Seems like it could be worth trying to do a visual/electrical check first.

 

[alexanderfoti]

CAN faults from the ESM are normally due to a failure inside the circuit board of the ESM rather than a cable issue, but best to check these first.

 

[Oddih]

Checked the status info. Calculated gear is inactive. Moreover, I also saw that when I selceted "C" the Transmission mode is indeed "Comfort", however, when selecting "S", the Transmission mode is Status Unknown.

 

[alexanderfoti]

Yes in that case, sounds like it spouting gibberish on to the canbus rather than a sensor giving issues.