Assembly, Diesel Exhaust Fluid Pump: Operation

The Diesel Exhaust Fluid (DEF) Supply Pump has many functions. It's primary purpose is to draw fluid from the tank and build adequate system pressure for dosing into the exhaust:

• The DEF Dosing Control Unit provides the 12 Volt supply and ground to the pump.
• The DEF Dosing Control Unit provides a Pulse Width Modulated (PWM) signal to the DEF Supply Pump to control the speed and output of the pump.
• The DEF Supply Pump has an internal temperature sensor which reports the internal temperature of the DEF Supply Pump to the DEF Dosing Control Unit.