Recently, I encountered a Scania P410 displaying an SCR fault code. After running diagnostics, I discovered the issue was caused by a faulty differential pressure sensor.
Today, I’ll explain what the differential pressure sensor is and how it works. I’ll do my best to keep it simple.
This sensor connects to two points: the upstream side before the DPF filter and the downstream side after the DPF filter. It compares the pressure of the exhaust gas before and after the DPF filter…
By measuring this pressure difference, the sensor can estimate the amount of Diesel Particulate Matter (DPM) trapped in the filter. It then sends a signal to the ECU to initiate the DPF regeneration process…
To put this in a real-life context, imagine you’re driving your Scania on the motorway and the stationary regeneration light pops up on your dash. This happens because the differential pressure sensor detects that your DPF is partially blocked and needs to be cleared to prevent serious problems.
I hope this helps you understand how this component works. All the best!