No auto box kick down.

[Stephen Rigby]

Hi hope your all well in the mad world.
I have a E270d salon auto 56 plate.I've had it 15mths It a a big old slug and runs fine. (The wife just plods around in it )
But The auto gear box does not kick down. I have to change up and down manually. It goes well and if you floor it from stationary it goes really well so I'm convinced that the turbo and the fuel system are working fine.
But it won't lock down and change fast ?
I've seen some post about the mass air sensor may cause it?
Thanks

 

[mioba]

MAF I doubt without getting codes read. Could be kick-down switch

 

[V6Matty]

When you accelerate when already moving does it change down gears at all, even if you press hard enough to activate the kick down switch (would usually then drop 2 gears)?
Having the codes read will be a good starting point here as the 722.6 is pretty reliable but if the box is in a soft limp mode then until you have the codes read your really guessing at a fix.
My guess here will be the pilot bush failing and atf wicking up the wiring into the gearbox ECU

 

[Wighty]

When was it last serviced , what’s the ATF level like ?

 

[Chrishazle]

When I first got my S203 C270Cdi it took a while to discover not only would it not kick down, it also would not go above 3k RPM. Luckily it came with a warranty so off to the garage, new MAF cured both problems.

 

[Stephen Rigby]

When was it last serviced , what’s the ATF level like ?

I've no service history. I'll check the fluid level Cheers

 

[Stephen Rigby]

When you accelerate when already moving does it change down gears at all, even if you press hard enough to activate the kick down switch (would usually then drop 2 gears)?
Having the codes read will be a good starting point here as the 722.6 is pretty reliable but if the box is in a soft limp mode then until you have the codes read your really guessing at a fix.
My guess here will be the pilot bush failing and atf wicking up the wiring into the gearbox ECU

No it doesn't change down.
But from stationary it changes up great .
Thanks

 

[Wighty]

I've no service history. I'll check the fluid level Cheers

You will need to buy an ATF dipstick from eBay

 

[Botus]

my fathers (280 v6 tractor) had no EML light and no go...

it was the senor that tells the VGT how much boost to give it, 10 mins and the car was back to normal... the "exhaust back pressure sensor" shows silly readings with the engine off - common issue £50 in stock at most dealerships.... plug in diagnostics and see what things it says are wrong

 

[V6Matty]

No it doesn't change down.
But from stationary it changes up great .
Thanks

Very much a case that you need to read the codes to find out what’s going on, but from there your then going to have to check the live data to confirm what’s going on to tell the box (or not as the case may be) to change down in acceleration,
As before my guess will be gearbox ECU being full of oil, though another option may be the throttle position sensor, either way live data will confirm