Automatic transmission seven speed gearbox fault

[Azmuf1]

I have a Maercedes Cla 2014 with a Intermittent fault when the car stops, or coming to a stop and when pulling off. The car shakes and get a warning sign do not change gears consult workshop. I need to switch the car off and on and then I can carry on driving as per normal.

I was taking it to the garage to have the fault looked at today and just before I arrived at the garage I had another error msg which read transmission malfunction in red when car was again at a standstill ready to pull off, Gearbox went into neutral, I had to put the car back in Drive and it drove fine. The fault is intermittent which is very annoying.

The garage connected the car with their star diagnostics however there was no error messages/codes referring to the Transmission.

The mechanic recommended it may be a idea to do a software update if one is available first to see if this rectifies the fault before looking any further as the diagnostics came back with no faults regarding the gearbox.

The car has just hit 120k and is due its 2nd gearbox service

Any advice will be appreciated especially if anyone has came across the same kid of fault.

 

[Oleks1992]

I have a Maercedes Cla 2014 with a Intermittent fault when the car stops, or coming to a stop and when pulling off. The car shakes and get a warning sign do not change gears consult workshop. I need to switch the car off and on and then I can carry on driving as per normal.

I was taking it to the garage to have the fault looked at today and just before I arrived at the garage I had another error msg which read transmission malfunction in red when car was again at a standstill ready to pull off, Gearbox went into neutral, I had to put the car back in Drive and it drove fine. The fault is intermittent which is very annoying.

The garage connected the car with their star diagnostics however there was no error messages/codes referring to the Transmission.

The mechanic recommended it may be a idea to do a software update if one is available first to see if this rectifies the fault before looking any further as the diagnostics came back with no faults regarding the gearbox.

The car has just hit 120k and is due its 2nd gearbox service

Any advice will be appreciated especially if anyone has came across the same kid of fault.

You needto get fault codes with star machine, common faults on these are valve bodies and dual clutch units wear, you should of had 3 gearbox oil services by now due to age

 

[Azmuf1]

You needto get fault codes with star machine, common faults on these are valve bodies and dual clutch units wear, you should of had 3 gearbox oil services by now due to age

Thank you for your response. The garage connected the star up to it but found no faults. The options they offered me were to check next week for any software updates first and then look at the valve body.
They were surprised that nothing came up on the star also

 

[markjay]

You needto get fault codes with star machine, common faults on these are valve bodies and dual clutch units wear, you should of had 3 gearbox oil services by now due to age

100% that only MB STAR will do the job.

However, if the garage offered to carry our a transmission software update, then presumably he would need to have a (genuine) MB STAR scanner? Unless he suggested that the car be taken to a dealer for the software update?

On a general note, the typical issues are lack of servicing (on a 2014 car, the ATF should have been replace twice, once in 2019, then again in 2024), or faulty transmission module (TCU). But, obviously, there may other issues.

 

[Azmuf1]

Thank you for your response
The garage do have the ability to do a software update as they are MB Specialists in Birminham.
What do you guys reckon with a software update.

Thanks for the info re atf servicing - i was under the impression it needed to be done every 60k

Appreciate the help guys.

 

[markjay]

I am note sure about the A-Class, but on the C-Class, the 7G+ transmission is due service every 77,500 miles or 5 years, whichever comes first.

 

[OneForTheRoad]

724 transmission is dct not torque converter type , it's every 62k or 5 years . It sounds very likely it needs a gearshift calibration, either that or possibly your clutch plates are worn out . Hopefully things will improve with a fluid change and a software flash....

 

[Azmuf1]

Update with regards to the fault
Garage had a look at it and have said the car is updated to the latest version so cannot do any updates, star has found no fault at all with the transmission. They have said they can do the gearbox service, however, they cannot confirm that this will resolve the issue.
They also said the star brought up one error msg regarding the charge movement flap on cylinder 1 has a malfunction however this has been there for five years & said they can repair that but are not convinced this will rectify the fault also.
Any suggestions as am stumped what to do next.
Thanks