Reductant Injector
WARNING: This page is about a different car, the 2013 Ford F-550 Super Duty, 2013 Ford F-450 Super Duty, 2013 Ford F-350 Super Duty, and 2013 Ford F-250 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.
The reductant injector is a pulse width modulated (PWM) solenoid controlled directly by the PCM. The injector receives diesel exhaust fluid (DEF) from the reductant pressure line and sprays it into the exhaust stream, where it is mixed into the exhaust gases before entering the selective catalytic reduction (SCR) catalyst.