211 engine light on

[alexmoon]

My W211 270 CDi's engine warning light has come on about four or five times in the last two months. It only happens sometimes when I kick down.
Light comes on, then puts me in limp home mode – which lets me rev to approx 2500 so it drives perfectly up to about 80 plus on the motorway. If I turn ignition off then start again then light goes off within a minute or so.
Other than that the car runs sweetly. Haven't had time to get it diagnosed. Anyway, two days ago light came on again and went in to limp home. Stopped a few miles on, switched off then on as usual but light remained on this time. However, kick-down worked now and I had full rev range. Light has stayed on ever since but car drives beautifully. Any idea what is happening?

 

[jasonyw]

Buy or rent a STAR from MB club. It most likely your MAF but then it could be a number of things. Without a STAR as used in MB dealer you are trying trial and error.

 

[st4]

Alex,

Take the car to the mercedes specialist in Ibrox and get the car looked at. Dave is very proffessional and given all your woes with the car needs looked at.

Steve

 

[alexmoon]

Steve,
If I have time will take it to him on Monday.

Cheers

 

[alexmoon]

Steve,
Took it to Ibrox yesterday but he couldn't plug car in as he was busy. Explained the problem and he reckoned it could be a turbo or EGR issue but would have to wait till it was Starred – fair enough. Then took it to a local who has Bosch diagnostics and fault that came up was 'Rail Pressure Monitoring'. He cleared the code and car has run perfectly again with engine light off. He told me to keep running it and see if light stayed off – might just be an electrical glitch. Local man said if it was an EGR problem then car would be running poorly. Also said that if it was a faulty turbo then engine wouldn't be doing full revs and kickdown etc. Local man seems to be making more sense than Ibrox. Steve avantgarde on other forum says: "Rail pressure variation fault codes store when the injector rail pressure drops below 250bar. It could mean the makings of a failing injector, high pressure pump or even as something as simple as a seal on a fuel pipe letting a tiny bit of air through." No mention of turbo or EGR so am a bit perplexed. Will keep an eye on it and let you know.