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Stan, Mercedes Technician
Category: Mercedes
Satisfied Customers: 3526
Experience:  Technical support engineer
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1995 w210 e420 gearbox issue,slipping gears,replaced box with

Customer Question

1995 w210 e420 gearbox issue,slipping gears,replaced box with a reclaimed one,same problem.Have had box stripped down at gearbox workshop and electric plate renewed,no faults showing on star but still the same original problem. It has been to two merc indie garages and they are both baffled with the way the gearbox is performing,any suggestions ould be gratefully received.
Submitted: 2 years ago.
Category: Mercedes
Expert:  Stan replied 2 years ago.
To avoid any confusion, please let me know the VIN of your car. I will check the exact transmission setup on your car

Customer: replied 2 years ago.
Hi Stan,thanks for response,as far as I know it's a 722.6. Vin No. WDB2100721A162114 the car is an import from Switzerland LHD. The only fault code is for brake/gear release which I was told would not have anything to do with the problem. Example if I drive off a roundabout and accelerate away the engine revs before thumping into a gear,this can happen during ordinary driving,as if the gear box does not know what the engine is doing. Thanks John
Expert:  Stan replied 2 years ago.
Hi John,
The problem can be in the faulty transmission control unit N15/3.
Click here for it's location.
It can be installed from a different vehicle for test, but will require coding with Stat Diagnosis to work 100% correctly. I have seen it cause transmission slippage.

Customer: replied 2 years ago.
Hi again Stan, you say change the gearbox ecu, does this have to be from exactly the same model or will any do from a Merc car with a 722.6 box. Thanks John