R230 722.6 gearbox not changing down on throttle?

[gramey]

So the first problem since I bought my R230 SL350 10 months ago has appeared, I left home and everything was fine for the first 8 -10 miles. I then came to a roundabout where I had to give way to an oncoming car. When I went to pull away the gearbox hadn't changed down and I crawled away slowly building up speed.
I continued my journey and there was traffic ahead, but if I dropped back a bit and depressed the accelerator it wouldn't change down, even if I hit the kick down. If I eased back but held the accelerator around half way sometimes it would change down but mostly not.
I pulled over and turned the car off, waited a few minutes and then started again, I accelerated briskly and the up changes appeared to be fine.
The only difference now was that the engine management light came on but it still wouldn't change down on the throttle. I tried manually shifting it down on the gear stick and it would change up and down fine but still the same if I put it in drive.
When I returned home from my fathers the car appeared to be fine again, kicking down when I wanted it to but the engine management light is still on. I shall see if my local indy can plug it in tomorrow and diagnose what the problem is but does anyone know what the likely cause would be?

 

[Joderest]

when was gearbox oil and filter last changed or level checked ?

 

[merc85]

Could be a conductor plate issue, quite common.

 

[BlackC55]

Any other lights that have popped up? Could be a variety of things but wheel speed sensors are common and can cause them to do all sorts of weird and wonderful things! That being said, you would normally have an ABS/ESP light on too but that isn't always the case!

Natacha

 

[gramey]

So a quick update, I popped it to my local indy this morning, Prestige Car Repairs in Ipswich and the seal on what Mercedes call a 'pivot bush', where the loom connects to the gearbox had gone and oil had crept up into the transmission ecu, t was also showing a throttle position sensor fault. They pulled the ecu apart and cleaned the small amount of oil out of it, replaced the pivot bush and cleared the fault codes.
The gearbox is now behaving fine, the engine management light had gone off when I started the car to take it down to them and the TPS fault code didn't come back up so they're not sure if the gearbox ecu caused it to throw a fault we'll just have to wait and see.
The gearbox oil is apparently very dark so it's booked in for next week for an oil and filter change as they didn't have time to do it today having already pushed back routine work to fit me in. Up until yesterday the box had shifted smooth as silk all the time I've had the car and hopefully with the oil and filter changed and leak fixed it will be silky smooth once more for a long time to come.

 

[merc85]

Thats a great result! It will be fine, Nice to hear she's back to how she should be