(47) DPF inlet and delta pressure sensors
(48) DPF inlet temperature sensor
(49) RF soot sensor antennas
(50) RF soot sensor monitor (remote mounted)
Note: The hardware for RF soot sensor monitor (50) may be present but is no longer operational.
The DPF system contains two types of filter media. The first filter media that exhaust gas is exposed to is the Diesel Oxidation Catalyst (DOC). This filter is a flow through style filter. The DOC is contained in the inlet section of the DPF cannister. The DOC filter contains platinum and palladium. The minerals aid in oxidizing hydrocarbons, carbon monoxide, and soluble organic fractions as the exhaust gas flows through the filter. The inlet section of the DPF cannister also contains the following items a temperature sensor, an RF radio frequency antenna, a pressure tap for the DPF inlet pressure sensor and a DPF delta pressure sensor. All four of these components are before the DOC. The purposes of these components are:
DPF inlet temperature sensor
measures the temperature entering the DPF cannister assembly. This temperature measurement is primarily used during regeneration. This temperature is used to control the ARD fuel and ARD air flow to maintain a desired DPF inlet temperature.
RF Soot Sensor Antenna
The hardware for RF soot sensor monitor may be present but is no longer operational.
DPF Delta Pressure sensor
The delta pressure sensor is also used to measure soot collected in the DPF. The delta pressure sensor is measuring the pressure drop across the DPF. Since the delta pressure sensor is measuring flow resistance across the DPF, the sensor will also detect ash loading.
DPF Inlet Pressure sensor
Used to measure the backpressure being generated by the DPF.
Once the exhaust gas flows through the DOC, the exhaust gas enters the DPF. The DPF is a ceramic filter. The DPF uses a wall flow design. This design is a porous wall structure which allows clean exhaust gas to flow through, but does not allow soot or particulate matter to pass.