Hello, everyone,

New guy here, I am stuck in a never-ending loop of issues with my 2014 ML350 Bluetec. It all started with a check engine light in December supposedly caused by the differential pressure and exhaust back pressure sensors - fault code 111500 'Soot content in the diesel particulare filter is implausible'. Changed both sensors to no avail. The DPF was not regenerating and fuel consumption was through the roof (23l/100) which made me install a brand new DPF. This solved everything up until this moment, fuel consumption stabilized, no more CEL.

Only 300 km later, another CEL came up, and shortly after, the dreaded Adblue Remaining Starts 10 message. Note that there was no prior Adblue-related message about "500 km remaining" or "16 starts remaining" - straight to 10 starts. At the time, I thought it was caused by low Adblue level, so I filled it up, which did not clear the CEL. Not only that, but the car started heavily smoking grayish/white from the exhaust and smelled as nothing I have ever smelled - neither diesel fuel smell nor ammonia (as fas as I could tell). After clearing the fault codes (16CE00, 16CF00), it all settled only for another 200km, before CEL came up again.

The official dealer advised me to perform a software update of the ECU since apparently the Adblue system was not properly communicating with the ECU - this fixed the Adblue-related codes, but I am now dealing with 14CF00 - 'The positive control deviation during exhaust gas recirculation control is too high' + 178200 - 'Efficiency of SCR catalytic converter'. The 14CF00 code prompts CEL and has been sporadically present ever since the DPF issues started in Decemver - the dealer claims I now have to clean the EGR valve, pipes, etc. This is fine and I will do it - my main worry is where does that damn smoke come from - could it be because of the EGR issue, the Adblue issues or the newly installed DPF? The smoke only started after filling the Adblue tank, but this was also shortly after DPF replacement which makes me think it could be either. The smoke comes up randomly during both highway and urban driving, lasts for about 2-5 minutes and stops. "Its just DPF regeneration" the dealer says, which doesn't seem plausible to me, given that its a new DPF and I never had such issues previously - only after the Adblue issues started.

Any advise would be appreciated.

 

I'm no expert but shortly after I bought my ML I started researching deleting these engines. I'm convinced that is the ikey to long life and troublefree ownership. It may not be an option - I'm not sure where you live - but if it is an option my advice is "Just do it". I had the work done at an Indie shop I trust but its not complicated - you could absolutely DIY. We used BuzzKen hardware and a Malone (Tunezilla) tune. That's 2 years ago now and zero related problems since. That's not to say zero problems but nothing related to the emissions system or the tune. My mileage is low 8 to high 7 litres per 100 km on winter fuel and down into the low 6s on summer fuel. The clincher for me was a conversation with my son who runs a fleet of relatively modern semi-tractors (30+ units) in western Canada. I asked him what his thoughts were. His response was that they run every truck bone stock until the first emission related problem at which point they completely delete them.

We installed a catalytic converter. I'm not sure if that's the reason but there's virtually no "diesel" stink when I start the car in the shop. I've owned lots of diesel pickups over the years - this ML doesn't smell half as bad as many of the Fords that preceded it. The BuzzKen hardware looks like a factory installation. You'd have to really know what to look for if you crawled underneath in order to know that the car doesn't have a factory exhaust. The only huge giveaway that we've done anything is the big AdBlue module unplugged in the right rear quarter panel That's completely hidden in the MB body panels and takes 15 or 20 minutes of work to even get a look at it. I use Xentry regularly and get clean emissions scans.