GTCpilot

This 2012 S350 with ~200K miles is occasionally shutting down when at low speed or idle.
Current error codes involve both high and low fuel rail pressures with mass flow sensor involvement and the dealer is just beginning to investigate.
I have been told by a MB mechanic that the Emission Campaign implemented from 2 years ago may be the culprit for shutting off. I recently received an unsolicited telephone call from a MB representative that the car was eligible for a current software update but NO info was given as to why, etc. I am reluctant to let any changes be made until I know why being done.Also, on occasion the vehicle also failed to initiate a start cycle when using either the push button or with key inserted in ignition. The fuse block start relay was recently replaced after these failures of the start sequence. The main battery is new as is the auxiliary.

Any Diesel owners experience the shutdown or start sequence issues??

BOTUS

You want the update (leaving the car deliberately broken is both stupid and illegal) - so the call wasn't unsolicited it is a legal MUST that Merc make the car legal (whether you like it or not...) or I guess you can officially scrap the car from use on public roads - there are a number of special extra in the current map (and if someone is offering to remove you should rip their hand off ASAP)

Merc fiddled emission control laws in part where the ambient temp sensor offsets the value the car's engine management believes it is - thus triggering a drive nicely illegal engine map - it’s the same idea GM used

VAG used a far better idea, noticing if the steering wheel is static yet the rest of the car is driving - it must be in the lab doing an emission test - so run the legal map, otherwise use one that drives nicely... USA protectionist trading practises found out about it, and used it to cripple the company as they had just become the world’s biggest Car Manu.

This is normal USA practise. It was the same when Toyota over took the big USA Car Manus and we had the fake Toyota death car debacle – where not a single car was dangerous or illegal. But 5 granddads had wedged a floor mat under a pedal they hadn’t pressed far for at least 15 years

BWM haven't been caught - I suspect because they used their brain and linked more than one fiddle - for example if both the steering and the suspension aren't moving we can run one map, but on the road we can pretend for road safely various maps get used at various times

Back to Merc - if it uses adblue depending on the market the car is being repaired in, it can mean they fit an unsuitable, but necessary map that’s legal but doesn't match various sensors already on the car (AKA mk1 or mk2 NOx sensors) the correct fix requires mk3 sensors, that they will not sell (or acknowledge exists) unless the parts listing is updated after applying a retrofit of special equipment code ‘30o’ via Vdoc – requiring dealer tooling and official logins

without mk3 NOx sensors its normal for the EML to come on shortly after the map update - where they try to extort $1000 from the owners by pretending its a separate unrelated issue - there are 4 software updates to complete the full fix - then they should (but don't) tell the owner - it will be operating in a special learning condition, where the gearbox will behave differently for a bit (9G boxes mostly) and the fuel and ad blue usage will be a bit higher - no one confirms, but quite likely the complete update means the DPF actually get a its first ever chance to complete a decent regen