Hi everyone, I have recently purchased a 2011 CLS 350 cdi (bluetec) with the 7-g tronic autobox, with 113k after a break from Mercs for a while as leased a car for a bit - it is great to be back behind a three pointed star... BUT on a couple of occasions the car has gone into some sort of limp mode, wouldn't change gear, wouldn't kick down, however no warning lights on the dash, and I managed to get the car to drop a gear using the flappy paddles eventually. When driven again soon after no problems at all. It has once or twice 'clonked' a bit going into top gear, but by no means regularly. Otherwise the car drives really nicely.
I did a bit of googling and I thought the symptoms were suggestive of the Conductor plate in the 722.9 autobox being faulty - lots of posts saying these sort of issues and that the conductor plate could be removed and sent off to be rebuilt (rather than buying a new MB one at significant cost). I bought an OBD scanner with transmission module capabilities and plugged it in but no transmission fault codes! It does have a lot of other data regarding the transmission though so I think it is reading OK, however there is a fault code 'Y77/1 Boost Pressure Positioner Fault' on the engine fault codes. Did I completely misread the symptoms and would this Boost Pressure Positioner fault cause the limp/no changing gear at all symptom?
Any help would be much appreciated, I don't have a particularly local Indy to take it to. Thanks Phil
I did a bit of googling and I thought the symptoms were suggestive of the Conductor plate in the 722.9 autobox being faulty - lots of posts saying these sort of issues and that the conductor plate could be removed and sent off to be rebuilt (rather than buying a new MB one at significant cost). I bought an OBD scanner with transmission module capabilities and plugged it in but no transmission fault codes! It does have a lot of other data regarding the transmission though so I think it is reading OK, however there is a fault code 'Y77/1 Boost Pressure Positioner Fault' on the engine fault codes. Did I completely misread the symptoms and would this Boost Pressure Positioner fault cause the limp/no changing gear at all symptom?
Any help would be much appreciated, I don't have a particularly local Indy to take it to. Thanks Phil