2018 OM654 W213 E220d Intermittent CEL & limp mode - P2227 Ambient Pressure

[n217970]

Hi all, scratching my head on this one hoping for some suggestions of things to look for? I'll try to give as much info as possible.

When starting from cold car runs great, no codes no CEL no problem. When I stop, to fill up with diesel for example, and get back in the car it drops into limp mode with CEL on, a quick restart clears the limp mode and CEL remains but it drives fine.

I sent it to a independent Merc specialist about 5 weeks ago who read codes - diagnosed a bad boost pressure sensor and ambient pressure sensor. Boost pressure sensor replace and software update. Problem persisted. They had it for another 5 days as couldn't diagnose further as the car was not in a fault state - seems it only faults for a fraction of a second on start up. They needed Merc tech support for advice. I think in desperation they changed the air filter in the end. This initially seemed to fix the problem for a couple of weeks. Last week the problem came back, I've read the codes myself and got

U0401 - Control Unit 5D Status: pending invalid data received - engine control module
P2227 - Control unit 58 Status : pending Barometric pressure (BARO) sensor - range/ performance problem.

I decided to have a look at the air filter and found it hadn't been fit correctly by the garage, the seal had been torn by being nipped where the filter housing joins. I replaced the filter. No change.

Reading live data from the engine ignition on, engine off
Ambient pressure 800 +-1
Boost pressure 800 +-1

Reading live data from the engine ignition on, engine on (fault - limp mode)
Ambient pressure 800 +-1
Boost pressure 800 +-1

Reading live data from the engine ignition on, engine on (after quick restart limp mode off)
Ambient pressure 1011
Boost pressure 1090

When I then turn the engine off these values stay similar for about 10 seconds before falling to the 800 values.

Garage want to change the ECU but I'm not convinced, the fact they can't fit an air filter correctly means it wont be going back to them. I also can't work out why if it were the ECU a new air filter fixed the problem for 2 weeks?

 

[n217970]

I've been out on my lunch messing with it again, deduced the following

With a warm engine, KOEO, when turned off for more then 10-15 seconds the pressure reading on the boost sensor both drop to 800 - starting in this condition results in CEL and limp mode. Turning off engine both sensors show a normal reading and restarting before the sensors show a pressure drop the car runs fine.
With a cold engine KOEO both show a normal pressure reading, starting in this condition car runs fine.

 

[n217970]

I know I'm not getting many replies here but would really appreciate an opinion on this, does anybody think this was changed a month ago?

I've had to give it a wipe to take a picture. From what I can see online 2017/2018 cars scrapped have sensors that start 17T whereas newer cars that number changes to 18T etc.

 

[spb]

Hi. I know this is an old thread, but what was the solutions to this issue. I'm getting P2227 and P0236 fault codes noting ambient and boost sensors. Also experiencing the same driving symptoms on my car. Would appreciate some info please from yourself or anyone thats had similar issues. Car is w213 220d 2017. Thanks.

 

[spb]

Update for people with similar issues. Quick check under the bonnet I found that the an air intake pipe to the resonator box was detached, pushed it back on and appears to have solved the issue.

Hopefully issue permanently sorted. Info might help others and save them money if garages are saying it needs new sensors , ecu etc.