Lazy 7G Tronic up shift

[Jay2512]

Hi All,

My C220 is due its first 15k service in a couple of weeks and wondered if to mention to the dealer that the 7G tronic box sometimes holds on to gears to long and seems not to want to change up a gear?

It mainly seems to be 1 to 2nd and 2nd to 3rd gear changes where the gearbox holds the gear and doesn't upshift till nearly 3000rpm which I regularly intervene and manually upshift if it will let me. This is all in E mode as I never use S.

Also on the odd occasion I do get a kick up the bum at low speed when it drops back in to first - but this happens mainly on a steep hill.

Would this be a simple software reset of the auto box?

And would this also reset the engine software?

 

[st13phil]

Are you sure this reluctance to upshift doesn't coincide with the DPF regen?

 

[Jay2512]

Are you sure this reluctance to upshift doesn't coincide with the DPF regen?

I would hope not....... Certainly no warning lights and the 15k miles have been 85% motorway.

There is no lack of power from the car, just if you drive steady it just holds on to the gear.

 

[st13phil]

Sorry, I should have been more specific.

When the car's engine management system decides to regen the DPF (happens on most cars every 300 - 600 miles depending upon use), the ecu commands the gearbox to upshift later to keep the rev's up. Once the regen is complete, the upshift points return to normal. There will be no warning lights, and no drop in power when this happens.

 

[Borys]

Have similar symptoms on my w221
Once plugged in star, electronic fault in gear box (that was recalled by merc).Unfortunately mine didn't had the privilege
Merc repair 1800 quid
Refurb 600 quid
Hopefully yours is a different problem

 

[Jay2512]

Sorry, I should have been more specific.

When the car's engine management system decides to regen the DPF (happens on most cars every 300 - 600 miles depending upon use), the ecu commands the gearbox to upshift later to keep the rev's up. Once the regen is complete, the upshift points return to normal. There will be no warning lights, and no drop in power when this happens.

Seems as though this is doing it more often than not.

Must admit when it is doing a regen the mpg drops off and a smell of what I can only describe as paint burning off metal.

 

[Jay2512]

Have similar symptoms on my w221
Once plugged in star, electronic fault in gear box (that was recalled by merc).Unfortunately mine didn't had the privilege
Merc repair 1800 quid
Refurb 600 quid
Hopefully yours is a different problem

I would hope nothing this bad - sorry to hear it cost so much Ouch!........

One good thing is I do have a warranty to make use of :bannana: