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mike_a_mechanic, Mercedes Mechanic
Category: Mercedes
Satisfied Customers: 5471
Experience:  17 years experience as a auto mechanic, foreign and domestic.5 years running my own repair business.
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Hello, I have a Mercedes powered motor

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Hello, I have a Mercedes powered motor home with a sprintshift gearbox.The motor is a diesel, 2.7. It was parked up for 2 months over winter and will now NOT select automatic although it can be driven manually. It is 8 years old ,in good condition with mileage of 26 thousand. I have been advised not to drive it manually until the problem has been identified as it may loose drive. I am told an ecu unit may be at fault. Any comments, solutions please. Robin XXXXXX

Hello, welcome. My name is***** will do my very best to assist you with your question. I apologize if you have been waiting long for a response.

Are there any type of warning lights coming on?
Customer: replied 3 years ago.


Hello Mike, no, there are no warning lights and the normal dash lights come on when the ignition key is switched on. The gear selected shows in the dash panel and changes when shifted manually to indicate which gear is selected. When in manual, as the vehicle slows for a turn, lights etc the gearbox downshifts automatically so all operates ok but still will not select auto when the lever is moved to the select position.


Trust that explains the position.

Since the vehicle has been sitting what normally causes this issue to happen is a stuck valve in the valve body, and what cures the issue is having the gear box fluid flushed and filled and this frees up the debris that is sticking the valve.
Customer: replied 3 years ago.


Thanks Mike, this is something I cannot attend to myself and will need the help of a garage so I will need to arrange that and see if it solves the problem.


I was told initially though that it may be electrical as the gears still operate.



Thank you, ***** ***** can respond back to this question at anytime after rating positive if you need further assistance.
Customer: replied 3 years ago.


Hello Mike,

I find it hard to rate your answer until I can arrange for your suggestion to be carried out and then I will be able to respond.



No problem, take your time. Thank you.
mike_a_mechanic and other Mercedes Specialists are ready to help you
Customer: replied 3 years ago.


Hello Mike,


I will respond to the rating so as to stop the bombardment of emails about your service. I am not unhappy but trying to put in context.


However, as my motorhome drives in manual but won't engage auto, do you see any problem in driving it and using it in manual until such time as I can have the gearbox drained? Also how do you "flush" the gearbox as against draining given that I have only done 26k mls and a gearbox change should last 70/80 k mls. Robin

Customer: replied 3 years ago.


Please see note below.

Sorry about the emails,they do not come from me,they come from the automated system. It will not harm the gearbox to drive in manual mode. The flush is performed with machine that sucks the old fluid out while adding new fluid. Thank you.
Customer: replied 3 years ago.


Thanks Mike, have arranged for a service next week will know if draining the gearbox was successful


Regards Robin.

No problem, thank you.
Customer: replied 3 years ago.


Mike, it required the ECU being reset. Thanks for your help.





Great. I'm glad the issue is fixed for you. Thank you.