E320/CDI gearbox speed sensor fault

[Striker99]

I drive an E320 CDI 2007. 3.0 V6 diesel.

A couple of times recently my gearbox has gone into limp home mode and when I have had the error codes interigated these come up

DTC 2767 Internal speed sensor
DTC 2768 Internal speed sensor
DTC 2767 RPM sensor 3

Can anyone help advise please on if the fix for this is a replacement speed sensor ? and if so if this is a big / expensive job or straightforward / inexpensive ?

 

[Striker99]

It would be helpful to know please where the speed sensor is situated so I know if the gearbox has to come out / be stripped etc ?

 

[David404]

Get it into an MB specialist who has a Star machine for definitive diagnosis.

For info: The 7G Tronic boxes are known to have problems if the gearbox oil and filter changes are missed. At one point MB said they were sealed for life, now I think they say service every 36,000 miles. Do you have any history on the car? Do you know when the gearbox was last serviced? If the servicing is ignored one of the common issues is with the conductor plate I think about £700.

BUT get it into a MB specialist for definitive diagnosis, you ned somebody with a MB Star machine and who knows MBs not just your local garage.

 

[chrisk2010]

Had the conductor plate on my 7G done plus internal and turbine sensors (electronic kit on the invoice), trans oil and filter change £795.00 about a three hour job.

 

[grober]

On the basis that picture is worth a thousand words---?
It can be done in situ- gear box pan dropped -valve body removed then conductor plate repaired / replaced

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[Striker99]

Get it into an MB specialist who has a Star machine for definitive diagnosis.

For info: The 7G Tronic boxes are known to have problems if the gearbox oil and filter changes are missed. At one point MB said they were sealed for life, now I think they say service every 36,000 miles. Do you have any history on the car? Do you know when the gearbox was last serviced? If the servicing is ignored one of the common issues is with the conductor plate I think about £700.

BUT get it into a MB specialist for definitive diagnosis, you ned somebody with a MB Star machine and who knows MBs not just your local garage.

I’ll check through the history I have for the car but I doubt very much the gearbox has been serviced within the last 36,000 in which case new gearbox oil & filter sounds like my first move !

 

[chrisk2010]

Just remember that the oil and filter need to come out to change the sensors.
If you only change the oil and filter you'll have to do it again if you do need to change the sensors.

The mileage on my car when the conductor plate and sensors failed was 37,500 so was do for a oil and tranny filter change couldn't say whether the two were linked or just coincidence.

 

[AMGeed]

Just remember that the oil and filter need to come out to change the sensors.
If you only change the oil and filter you'll have to do it again if you do need to change the sensors.

The mileage on my car when the conductor plate and sensors failed was 37,500 so was do for a oil and tranny filter change couldn't say whether the two were linked or just coincidence.

As above, you could be wasting the best part of £200 having the ATF changed when the speed sensor could be faulty.