What's actually happening
Euro 6 diesels are legally required to prevent restarts when the SCR system reports it isn't working correctly. The vehicle warns you for a defined number of miles, then engages the lockout when the countdown expires.
Nothing is mechanically broken by the lockout itself. Once the underlying fault is repaired and the system re-validates in live data, the vehicle starts and drives normally again.
Common causes behind the lockout
- A NOx sensor fault, upstream or downstream, or its wiring
- Under-dosing from a failing pump or a crystallised injector
- Level, quality or heater sensor faults inside the tank
- Poor quality or contaminated AdBlue fluid
- A previous repair where the code was cleared but the cause remained
What not to do
- Don't keep cranking — you'll flatten the battery and add more faults
- Don't pay someone to simply clear the code; the lockout returns
- Don't pour extra AdBlue in hoping it resets if the tank was already full
- Don't have it recovered to a garage before it's diagnosed — most of this is fixable where it stands
How we get you moving
- 24/7 mobile attendance at your home, work or roadside
- Full fault memory and live-data diagnosis on site
- Cause explained in plain English with a quote before work
- Repair and verification, then the lockout is cleared properly
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