Active DPF Differential Pressure Sensor Out of Range

The differential pressure sensor measures the difference in pressure before and after the DPF. If the value is too high or too low, it indicates a problem with the DPF or the sensor itself.

The electronic control unit (ECU) looks for the differential pressure to be within a specific range, typically between 0 to 50 kPa under normal operating conditions. If it sees values outside 0.5 kPa to 35 kPa, it records a fault.

Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.

1. 11. Inspect the wiring and connectors to the differential pressure sensor for damage or corrosion. Repair as needed. Decision: Are the connections intact? If yes, proceed to step 2; if no, repair and recheck.
2. 22. Check the DPF for excessive soot accumulation. If the filter is clogged above manufacturer specifications, perform a forced regeneration or replace the DPF. Decision: Is the DPF clean? If yes, proceed to step 3; if no, clean or replace the DPF as needed.
3. 33. Measure the differential pressure sensor output using a scan tool while the engine is running at various RPMs. Compare the readings to expected values. Decision: Is the pressure reading within 0.5 kPa to 35 kPa? If yes, proceed to step 4; if no, replace the faulty sensor or wiring as indicated.
4. 44. If the DPF and sensor are both functioning correctly, connect the ECU to check for any software updates or faults. Decision: Are there any new codes or updates? If yes, follow manufacturer guidelines; if no, further investigate potential ECU issues.

• Faulty differential pressure sensor
• Clogged diesel particulate filter (DPF)
• Damaged wiring or connectors to the sensor
• Exhaust leaks before or after the DPF
• Faulty ECU programming

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