S212 E300 Hybrid transmission problem

[jbrameld]

I have a 2014 (64 plate) E300 Hybrid and the 7-speed automatic transmission (724.208) is giving me a bit of trouble. It won't change up until around 2800 revs and some of the down changes are a bit jerky too. The hybrid system and electric drive part dropping out and in is all still working OK though - it just seems to be the transmission.

Similar problems on non-hybrids (with the 722.9 transmission) seem to be either the O-Ring seal on the valve body multipin connector, or the TCM conductor plate going faulty. This started as occasionally intermittent (which would fix itself usually after a few minutes) but it's now permanent and that seems consistent with the stories around the O-Ring and/or TCM conductor plate.

My local garage are a bit reluctant on this one as it's automatic and pointed me at a transmission specialist. They are also reluctant as it is a hybrid but said to clear the fault codes and see what comes back (which I have done - the previous fault codes were an oil pressure switch electrical fault and a steering column module comms fault) and await to see if anything returns.

To me it seem likely the cause may be the same as on the non-hybrid transmission, but does anyone have any other ideas My local garage did say they could check a couple of things given some pointers, and I can get the TCM tested and repaired for around £200-ish so it may be worth trying that route. Any recommendations for who I could take it to who won't run away (preferably not a main dealer who'll probably tell me I need a new transmission!) also gratefully received.

I'm based near J18 of the M25 in Hertfordshire.

Thanks,

Jason.

 

[Blobcat]

When was the atf last changed?

 

[mioba]

The O ring on the connector should be a service item at ATF change.

They fail and its an easy job while changing the ATF.

Are you handy with cars?

 

[jbrameld]

Looking at the service history I don't think the ATF has ever been changed, and it should have been done at around 75k-ish? Current mileage is around 88k.

I used to tinker with cars a fair bit but I'm too old for lying on the floor underneath them these days - but with a good steer I expect my local garage would help me out. Should I just go for a fluid and o-ring change, or is it worth getting the TCM sent off while the fluid is out and the sump pan is off? The TCM can be tested and returned if not faulty.