Plenty of A240 miles, so why the AdBlue fault?
Drivers from Worcester Park are sometimes puzzled by an AdBlue fault. Their diesel isn't a school-run car. Many households here run two cars, and the diesel is often the one kept for longer journeys. It regularly heads out along the A240 to join the A3, or past Nonsuch Park towards Ewell, runs at a steady speed and gets thoroughly hot, which is exactly what an SCR system likes. So why the warning?
The answer is usually wear rather than use. A diesel that covers big mileages reaches the age where the AdBlue pump, the tank heater or a NOx sensor simply comes to the end of its life. Wiring and connectors under the car take years of spray and road grime, and a poor connection can produce faults that come and go. Crystallisation still happens on high-mileage cars too, often from a slow leak at a joint rather than short trips.
Because the fault could be almost anywhere in the system, we test it in order. Codes and freeze-frame data first, then the dosing test, pump pressure and heater current, a close look at the wiring and connectors, and finally the fluid itself. That tells us whether a single component has failed or something else is causing it. Where a fault only appears on longer drives, we road test the car for long enough to reproduce it. You get a written quote before we fit anything, and a 3-month workmanship warranty afterwards.
Around Central Road and the wide 1930s streets near Christ Church with St Philip, cars are often parked on both sides, so if the countdown has already reached zero, recovery is the practical option. Otherwise the drive is about 6 miles: Cheam Common Road to the North Cheam crossroads, Malden Road to Cheam Village, then the A232 through Sutton and Carshalton. From the Motspur Park side, allow a few minutes more, and avoid the camera-enforced bus gate on Browning Avenue unless you have an exemption.