W212 350cdi AMG sport - reluctant to change up

[Merc320_John]

Had car a few months and I have driven it with a light foot. Gear changes always took place at sub 2000rpm it has just started holding till Abt 2700rpm before it will change up gears still driving with light foot. Using the paddles changes up immediately. If I switch to sport or manual mode it still seems to change up at 2700rpm (with light foot).
As an aside I started it this morning and it displayed an engine management fault my diagnostic tool gave P200a fault but said that code was not in directory. Cleared fault code, drove a few miles but after I stopped and restated engine the same engine mgmt code appeared.
If anyone can help with suggestion thanks in advance.
John

 

[onefortheroad]

What does a P200A code mean?

Intake Manifold Runner Performance

Diagnostic trouble code (DTC) P200A stands for “Intake Manifold Runner Performance (Bank 1).” This code is logged when the powertrain control module (PCM) has detected a problem with the intake manifold runner control (IMRC) system. This code is also logged when the intake manifold runner does not operate as it should.

 

[Merc320_John]

Thanks for that info on the code.

Does anyone have any ideas on gear change problem?

 

[Capra]

Mine started doing this just before refusing to change up from second, then finally 1st. It turned out that I had a failed EGR valve. Probably not your problem, but I thought the worst thinking it was a gearbox issue.

 

[Merc320_John]

It seems that both my problems might be possibly related.
Having taken the car to an independent Mercedes mechanic he drove the vehicle he told us it was in limp mode which surprised me a bit having taken the car for a motorway trip to visit mother-in-law possibly completing a Regen (a guess) covering 100 miles round trip and returned 46mpg. I thought it was a bit down on power but thought it was because I wasn't changing down using the paddles. The mechanic proposes to disconnect imrc and insert a resistor assuming this is what puts the car into limp mode which he says will cause gearbox issues. We shall see on Friday and let you know.
My experience of limp mode with my old Range Rover is that car only did 30mph not 70 as with merc.

Capra maybe you were in limp mode too?


Regards John

 

[Capra]

It seems that both my problems might be possibly related.
Having taken the car to an independent Mercedes mechanic he drove the vehicle he told us it was in limp mode which surprised me a bit having taken the car for a motorway trip to visit mother-in-law possibly completing a Regen (a guess) covering 100 miles round trip and returned 46mpg. I thought it was a bit down on power but thought it was because I wasn't changing down using the paddles. The mechanic proposes to disconnect imrc and insert a resistor assuming this is what puts the car into limp mode which he says will cause gearbox issues. We shall see on Friday and let you know.
My experience of limp mode with my old Range Rover is that car only did 30mph not 70 as with merc.

Capra maybe you were in limp mode too?


Regards John

I certainly was, but I was unable to do more than 15-20 mph, so quite a severe limp mode. I had to be towed.

 

[onefortheroad]

It seems that both my problems might be possibly related.
Having taken the car to an independent Mercedes mechanic he drove the vehicle he told us it was in limp mode which surprised me a bit having taken the car for a motorway trip to visit mother-in-law possibly completing a Regen (a guess) covering 100 miles round trip and returned 46mpg. I thought it was a bit down on power but thought it was because I wasn't changing down using the paddles. The mechanic proposes to disconnect imrc and insert a resistor assuming this is what puts the car into limp mode which he says will cause gearbox issues. We shall see on Friday and let you know.
My experience of limp mode with my old Range Rover is that car only did 30mph not 70 as with merc.

Capra maybe you were in limp mode too?


Regards John

You usually lose all turbo boost and very late gear changes . If you didn't realise ,you mustn't of done any overtaking , the difference is night and day tbh. Resistor mod is for swirl flaps ,if they jam , the car goes into limp mode.