Our services
Adblue Faults
AdBlue Fault Diagnosis and Repair
Fleet Services Autocare Limited diagnoses and repairs AdBlue (SCR) system faults at customer premises across Berkshire, Hampshire and Surrey. If a warning has appeared on your dashboard, it's worth acting promptly - left unresolved, an AdBlue fault will eventually stop the vehicle from starting at all. We come to you, diagnose the fault on site, and repair it using genuine parts.
What Is AdBlue and the SCR System?
AdBlue is a fluid used by most modern diesel vehicles to cut harmful exhaust emissions. It's stored in its own tank, separate from the diesel, and injected into the exhaust through the SCR (Selective Catalytic Reduction) system, where it converts nitrogen oxides (NOx) into harmless nitrogen and water.
It's a legal emissions requirement on diesels from around 2015 onwards, which is why the system can't simply be switched off or ignored. When something goes wrong with it, the vehicle is designed to warn you, then progressively force the issue until the fault is fixed.
Get In Touch
We're trusted by businesses and drivers across Berkshire, Hampshire and Surrey to keep their vehicles serviced, maintained and on the road.
Phone: 0118 973 0157
Email: Online Contact Form
Why You Shouldn't Ignore an AdBlue Warning
This is the part that catches operators out. AdBlue systems are designed to enforce repair through a countdown: once a fault or low fluid level is detected, the vehicle warns you, then displays a reducing range - for example "no restart in 800 miles" - counting down as you drive.
When that countdown reaches zero, the vehicle will not restart once switched off. It becomes immobilised wherever it happens to be parked, until the fault is resolved. For a working van, that's not an inconvenience - it's a vehicle stranded mid-shift, a driver stood down, and a recovery cost on top of the repair. The warning is the vehicle giving you time to act; the time is best used early.
Common AdBlue Faults We Diagnose
AdBlue warnings cover both simple and complex faults. The ones we see most often include:
Low AdBlue level - sometimes simply needing a correct refill, though warnings can persist if there's an underlying sensor fault
NOx sensor faults - a very common cause; these sensors fail with age and trigger warnings and limp mode
AdBlue injector or dosing faults - blocked, leaking or failed injectors
Crystallisation - AdBlue can crystallise around injectors and lines, causing blockages
AdBlue pump and heater faults - the system is heated because AdBlue freezes in cold weather; heater failures cause faults in winter
Level sensor and tank faults - incorrect readings even when the tank is full
Wiring and electrical faults in the SCR system
Because a single AdBlue warning can stem from any of these, accurate diagnosis matters - guessing at parts here is expensive.
Frequently Asked Questions
What happens if I ignore an AdBlue warning?
The vehicle counts down a reducing range and, once it reaches zero, will not restart after being switched off - leaving it immobilised until the fault is fixed. Acting early avoids a stranded vehicle and recovery costs.
Does an AdBlue warning just mean I need to top up the fluid?
Sometimes, but often not. Warnings are frequently caused by sensor, injector or dosing faults that a refill won't clear. We diagnose the actual cause rather than assuming it's the fluid.
Why does AdBlue diagnosis matter — can't you just replace the part?
It's tempting to assume a warning just means "add fluid", but topping up a system with a failed NOx sensor or blocked injector simply leaves the warning in place and the countdown running. Equally, replacing a NOx sensor that wasn't at fault is a costly mistake, as these aren't cheap parts. We diagnose the actual cause using equipment that reads the SCR system's live data, not just the stored code - so the fault is fixed once, rather than paying for parts that were never the problem.
What's the most common AdBlue fault?
NOx sensor failure is among the most common, particularly as vehicles age. These trigger warnings and often put the vehicle into limp mode, and they're not a part worth replacing on guesswork — accurate diagnosis comes first.
Can you fix an AdBlue fault at my premises?
Yes. We carry out AdBlue diagnosis and repair on site across Berkshire, Hampshire and Surrey - at your home, depot or workplace. Where a part needs to be ordered, we diagnose on the first visit and return to fit it, using genuine parts so the repair lasts. If your vehicle is already showing a no-restart countdown, tell us when you call so we can prioritise getting to you before it reaches zero.
My van won't start because of AdBlue - can you help?
Yes. Call us with the details and we'll get to you as quickly as we can. If the vehicle has already immobilised, we'll diagnose and repair the fault on site to get it running again.
Do AdBlue faults affect whole fleets at once?
They can. NOx sensors in particular have a finite life and tend to fail as vehicles age - often across several vehicles bought at the same time. We diagnose and repair faults on site, and as part of a planned maintenance arrangement we can help keep AdBlue issues from becoming unplanned no-starts.
