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AdBlue faults
AdBlue warning or countdown? Don't wait for zero.
Many diesels show "No start in 500 miles" when the AdBlue system has a fault. We find what has failed and fix it properly.
What AdBlue does
AdBlue is a fluid sprayed into the exhaust of modern diesels to cut harmful gases. If any part of the system fails, the car warns you, and many cars start a countdown. When it reaches zero, the engine may not restart. Topping up the AdBlue rarely fixes a fault warning.
Signs to look out for
- "AdBlue system fault" or "No start in X miles" message
- AdBlue warning light on
- Car in limp mode or down on power
- White crystals around the AdBlue filler or injector
- Warning came back after topping up
Book in now. Once the countdown reaches zero the car may not start, and you could be stuck. If it has already hit zero, call us and we'll talk through the options.
What usually causes it
- Blocked injectorAdBlue crystals build up and stop it spraying.
- Pump or heater failureCommon in cold weather, as AdBlue freezes.
- NOx sensor faultsThe sensors that check the exhaust stop reading properly.
- Bad fluid or softwareContaminated AdBlue, or errors inside the ECU.
Find the cause first
How we fix it
- Read the codes and dataWe check every AdBlue code and how the system is behaving.
- Test the partsInjector, pump, heater and sensors, so we only replace what has failed.
- Fix and resetRepair, reset adaptations and clear the countdown properly.
Your options
Recommended
Book us
Bring it to our HQ at Mallory Park. You get a price before any work starts.
Book a check →Fix it yourself
AutoTuner One, from £365
Some AdBlue faults are software. A plug-in AutoTuner One may fix it at home. Sold through our sister brand DIY AdBlue Fix. Tell them your car first and they'll confirm it's right before you pay.
See DIY AdBlue Fix ↗Common questions
Will topping up the AdBlue fix it?
Only if the tank was empty. A fault warning usually means a part or the software has a problem, so a top-up won't clear it.
Do you remove AdBlue systems?
No. Removing AdBlue is illegal on UK roads and the car fails its MOT. We fix the system so it works properly.
What if the car won't start?
Call us. We're based at our HQ, but we'll talk through the options for getting it to us.
How long does a repair take?
Many faults are fixed the same day. If a part has to be ordered, we'll tell you how long before we start.