MajorCommonEngine

Mercedes-Benz Sprinter: VS30 AdBlue/SCR system faults — NOx sensors, pump and crystallisation

VS30 AdBlue/SCR system faults — NOx sensors, pump and crystallisation is a common engine fault on the Mercedes-Benz Sprinter on the 2018 onward cars, and we rate it major. Putting it right costs $600 to $3,000 at New Zealand independent workshop rates. Below is what goes wrong, the symptoms to notice on a test drive, where to look, and what to ask the seller before you hand over any money. It is one of 15 documented faults on the Mercedes-Benz Sprinter.

Vehicle: Mercedes-Benz Sprinter
Years: 2018 onward
Fuel: diesel
System: Engine

This page covers the Mercedes-Benz Sprinter as a model. Some faults only affect particular engines or build years — enter a plate below to narrow the list to one car.

All Mercedes-Benz Sprinter faults15 documented faults on this model

What you are looking at

No photograph available

We do not hold a verified photograph of the Fuel injector yet. We would rather show none than show a picture of a different part.

What goes wrong

AdBlue system faults are the single most-reported problem on the 2018+ VS30 Sprinter: failing NOx sensors, a tired AdBlue pump, or crystallised fluid at the injector trigger warnings and a start-countdown ('no restart in X starts'), after which the van will not start. Short journeys and long storage (typical camper use) make crystallisation worse. NOx sensors are several hundred dollars each; pump/injector jobs run over a thousand.

What you would notice

'AdBlue system fault' warning
'No restart possible in X starts' countdown
Reduced power / limp mode
AdBlue gauge stuck or misreading

How to check it

Where to look. AdBlue tank and pump under the van; NOx sensors in the exhaust; filler beside the diesel cap

Check the dash for any AdBlue/emissions messages and confirm the countdown is not active.
Ask for invoices for NOx sensor or DEF pump replacement.
For campers that sit unused, ask how old the AdBlue in the tank is — stale fluid causes faults.

Parts involved: Fuel injector.

What it costs to put right

$600 to $3,000 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

Ask the seller

“Any AdBlue faults or NOx sensor replacements?”
“Has it ever gone into a start countdown?”

Now check the Mercedes-Benz Sprinter you are actually looking at

Everything above is true of the model, and it is free. What it does not tell you is whether THIS car has been looked after: its odometer history and whether the reading has ever gone backwards, whether there is still money owing on it, whether it has been reported stolen, how many owners it has had and what it is really worth today. That comes from the official records for that plate. Enter the plate for the free details, or get the full history and a market valuation from $13.49.

Not sure what you would be paying for? See what a full KickTyres check includes.

Where this comes from

The failure described above is documented in the sources below. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them.

Sprinter-source.com VS30 AdBlue/NOx fault threads
ifixadblue.co.uk Mercedes Sprinter AdBlue troubleshooting guide
mercedesmedic.com Mercedes AdBlue problems

Mercedes-Benz Sprinter buyer questions

Is vs30 adblue/scr system faults — nox sensors, pump and crystallisation serious on a Mercedes-Benz Sprinter?

We rate it major and common on the Mercedes-Benz Sprinter. AdBlue system faults are the single most-reported problem on the 2018+ VS30 Sprinter: failing NOx sensors, a tired AdBlue pump, or crystallised fluid at the injector trigger warnings and a start-countdown ('no restart in X starts'), after which the van will not start. Short journeys and long storage (typical camper use) make crystallisation worse. NOx sensors are several hundred dollars each; pump/injector jobs run over a thousand.

How much does it cost to fix on a Mercedes-Benz Sprinter?

$600 to $3,000 at New Zealand independent workshop rates. That figure is for this job on its own. A car showing the symptoms on this page is usually worth either walking away from or negotiating down by at least the repair figure.

Which Mercedes-Benz Sprinter years are affected?

Our research records this fault on the 2018 onward Mercedes-Benz Sprinter. Build dates move around, especially on imported cars, so treat the range as the years to look hardest at rather than a guarantee either way. The official records tell you the exact build and first registration date for the car in front of you.

How do I check for it before I buy?

Check the dash for any AdBlue/emissions messages and confirm the countdown is not active. Ask for invoices for NOx sensor or DEF pump replacement. For campers that sit unused, ask how old the AdBlue in the tank is — stale fluid causes faults. Look here: AdBlue tank and pump under the van; NOx sensors in the exhaust; filler beside the diesel cap