Replacement of the Diesel Exhaust Fluid (DEF) Filter

The Environmental Protection Agency's 2010 and later regulations require lower nitrogen oxide (NOx) exhaust emissions. Selective catalytic reduction (SCR) uses diesel exhaust fluid (DEF) to lower NOx emissions in the vehicle exhaust. A filter in the DEF pump prevents clogging of the DEF metering unit injection nozzle.

See the engine manufacturer's maintenance manual for filter replacement instructions and maintenance intervals.