Circuit/System Description

For an overview of the component/system, refer to: Exhaust Aftertreatment System Description

The reductant pump is commanded on by the control module to pressurize the reductant to a predetermined pressure within the reductant fluid pipe. The control module then uses the reductant injector to perform a controlled injection. The control module calculates the amount of reductant delivered by monitoring the pressure drop inside the reductant fluid pipe during the test. The control module then compares this calculated value against a calibrated threshold. If the result is not within the expected range this DTC will set.