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7 Answers

Slip into Neutral Mercedes E500 2003 722.6

Asked by: 40 views Transmission question

Hi, I have a Mercedes e500 2003, I was driving up an inclined road when a whining sound occured , the gear seems to slip to Neutral cause after that the car is no longer driveable (i.e. as I press the gas pedal, the RPM goes up, but the car does not move and the shifter is in Drive). The i980 scanner shows the P0730 OBDII code, there is no mercedes error code available , any thoughts on what could have caused the problem is appreciated. THanks.


7 Answers

  1. 0 Votes Thumb up 0 Votes Thumb down 0 Votes

    Is there still any weird sounds coming from the transmission?
    The P0730 code is set when the transmission is slipping yes. What you could do is to check your transmission oil and see if there are any metal pieces in the transmission oil.

    You can also check the 13 pin plug on the transmission for any oil leakage inside the plug, but because the sound you experienced, it seems more like a mechanical problem.

    In this case, I recommend you to take it to a good transmission repair workshop for proper diagnostics.

    This is a service bulletin from WIS (Mercedes)

    Target gear is not reached, transmission in mechanical/hydraulic limp-home mode
    Fault code:
    055 I5I P0 730
    Possible cause / Remedy
    •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).

    Ask A Mechanic Admin - Apr 10, 2018 |Reply

  2. 0 Votes Thumb up 0 Votes Thumb down 0 Votes

    Thanks for the response.

    There is no weird sound,  I heard whining sound but that is probably coming from the car slipping into Neutral and me pressing the gas pedal (I did not realize that it slipped into Neutral) causing the Engine to rev up above 2000 rpm.

    Following your answer, I replaced  the conductor plate, solenoid Y3/6y2  the transmission oil filter (and of course – replaced about 5l of  the transmission fluid). I did not replace the 13-pin adapter plug since it was dry.

    I also did a glycol test using Accustrip’s ATF glycol test strip, and  there was not sign of glycol contamination.

    I drove the car about 15 miles, and it was running smoothly for now. Is  there is a way to read collected data from a scanner to determine that the transmission is running properly ? (I think the 722.6 has adaption data – such as fill pressure when shifting gears – that  can help determine if the transmission has worn clutch, leaking sealing rings, etc…, But I don’t know the correct range for this w211).

    Many thanks

    pault - Apr 10, 2018 |Reply

  3. 0 Votes Thumb up 0 Votes Thumb down 0 Votes

    Yes depending on your DTC tool, you can read a lot of data from the transmission control.

    If you have a good DTC tool that is working good for your car, you can see all the temperatures and such. I can also recommend doing an adaption and adaption reset after any work with an automatic transmission.

    The transmissions are very smart, if there is any strange values the transmission control unit will most likely recognize it itself and make it to a DTC code.

    Ask A Mechanic Admin - Apr 11, 2018 |Reply

  4. 0 Votes Thumb up 0 Votes Thumb down 0 Votes


    I thought the problem was resolved after replacing 6y2, conductor plate, transmission filter. However, after a long drive, the problem reoccurs, this time however, there is no error code, just simply, the transmission does not shift into a target gear  (i.e. target gear is drive or reverse, but actual gear is either Park or neutral ), any thoughts are appreciated.

    pault - Apr 19, 2018 |Reply

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    I drove some more about 30 minutes after reporting the issue on 19 april @ 19:18. Despite of the car getting into this quasi limp mode (i mentioned quasi because the car could go up to 3rd and 4th gear,  and I can drive longer distance in the 3rd and 4th gear before I get implausible gear ration where the actual gear starts to slip to neutral) , I was able to get home  (about 10 miles from the location where the problem re-occured) by stopping and restarting the car. I got the following Mercedes specific codes : 2502, 220a, and ODBII code P0730, P0715. The P0715 came up once then disappeared. Any suggestion is very much appreciated.


    pault - Apr 19, 2018 |Reply

  6. 0 Votes Thumb up 0 Votes Thumb down 0 Votes

    When the problem occurs/If it does for a long time, You can check the parameters in the transmission control module. Check if the gear position sensor is giving you the right signal. Check if it says “Neutral” when the stick is at Neutral etc

    Ask A Mechanic Admin - Apr 20, 2018 |Reply

  7. 0 Votes Thumb up 0 Votes Thumb down 0 Votes

    Yes, I did check, the actual gear does not follow the shift stick, the computer target gear (i.e. the shift stick is in drive, target gear is 2 which is correct since I set the transmission for winter drive mode, but the actual gear is neutr al. Another example, the shift stick and target gear is in reverse but the actual gear is park.) . The issue occurs after driving more than 10 miles (- when the transmission is hot), could it be that the line pressure solenoid (6y1) behaves badly when transmission is hot?


    pault - Apr 20, 2018 |Reply

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