SCR system uses DEF (diesel exhaust fluid) also called Adblue to ensure truck emissions are maintained within the set standard. If truck runs out of Adblue or if SCR related fault occurs, the truck’s performance/power will be limited (limp mode) until the problem is resolved.
Adblue emulator is a small, electronic device normally installed by connecting it to power supply and CAN lines. Once installed, adblue emulator sends signals to the truck’s ECU imitating the signals that would normally be sent by numerous sensors within the SCR system, indicating normal SCR system performance. Simply put, adblue emulator fools the ECU in thinking everything within the SCR system is working as should when in fact SCR system is disconnected or even removed from the truck altogether.
Adblue emulators would normally be installed to trucks going for export or trucks operating in countries where European Emissions standards are not in force. The use of adblue emulator in the UK and within the EU is illegal.