What happens when fault code 1922 is active? The ECM activates the fault codes based on the measured pressure difference across the DPF. If the soot load is high, a higher pressure difference is observed, because the accumulated soot will provide a restriction to flow on the DPF inlet side (Inlet pressure > Outlet pressure).ĭuring engine testing, the Cummins engineers have determined the allowed pressure difference levels on the DPF.

Naturally, a small pressure drop is always expected even on new DPFs, due to the fact that the exhaust gases are foreced to flow through the DPF walls. The sensor performs the following simple mathematical function:ĭPF Pressure Difference = – Soot load is estimated by the ECM, by monitoring the inlet and outlet pressure of the filter. If the soot load on the DPF is high, the ECM will activate the DPF system warning lamp on the dashboard. idling) might require a stationary regeneration, due to the fact that the average temperatures on the DPF are not enough to allow soot to be burned off passively. During passive regeneration, soot is burned-off from the inlet of the filter and extend its service life.Įngines that operate longer periods on light loads (eg. Typically, the engine operating conditions generate high temperatures and allow the passive regeneration of the DPF (self-cleaning).

The ECM constantly monitors the soot load of the DPF. +5 Volt supply, ECM Return, DPF outlet pressure signal, DPF differential pressure signal.ĭPF Differential pressure sensor circuit function Important to note: The vehicle or machine manufacturer is responsible to construct the wiring harness and allow the sensor to eventually connect to the ECM. The two pipes allow exhaust gas pressure from the inlet and outlet of the DPF respectively to reach the sensor.

It is not easy to miss – there are two flexible pipes connected on the sensor body. The sensor is located on the Aftertreatment system, mounted directly on the DPF. The soot load of the Diesel Particulate Filter is monitored by the DPF differential pressure sensor. To protect the engine, the ECM activates the power derate. Cummins fault code 1922 becomes active when the soot load of the Diesel Particulate Filter (DPF) has exceeded the recommended limits.

Cummins insite fault codes