How does ad-blue work?

Vehicles with SCR technology have a separate tank filled with Adblue. This is then injected into the exhaust pipe, in front of the SCR catalyst, downsteam of the engine.

Heated into the exhaust, it decomposes into Ammonia and CO2, when the NOx from the engine reacts inside the catalyst with the ammonia the harmful NOx molecules are converted into harmless nitrogen and water, which  then leave the exhaust as steam.

What happens if it stops working?

A recent change in the law means if your Adblue stops working and the engine warning lamp or Puff light is showing on the dash, firstly the vehicle will fail its MOT, or the potential for a prohibition notice to be issued on the side of the road. It is also highly likely to put the vehicle into limp mode and also causes harmful NOx to be allowed into the atmosphere.

Can we fix the Adblue?

Yes, the Adblue system is normally trouble free, but when it goes wrong it can be expensive to fix.

SNJ Auto Electrics Ltd have extensive knowledge of the systems on HGV and PSV vehicles and are able to repair or advise the customer of particular items that are required using upto date diagnostics and knowage to get your vehicle back on the road as quickly as possible.