The Differential Pressure Sensor (DPS) plays a vital role in monitoring the performance of the Diesel Particulate Filter (DPF). It measures the exhaust gas pressure both upstream and downstream of the DPF. By comparing these two readings, the DPS helps determine the saturation level of the DPF so the engine control unit (ECU) can trigger Diesel Exhaust Fluid (DEF) injection and manage filter regeneration efficiently.
Accurate DPS readings ensure the DPF operates correctly—maintaining engine performance, controlling emissions, and preventing costly damage to exhaust components.
How It Works:
- Measures pressure differences before and after the Diesel Particulate Filter (DPF).
- Sends a signal to the ECU, which interprets the data to detect DPF restriction or soot buildup.
- The ECU adjusts regeneration cycles and DEF injection timing based on the sensor’s readings.
- Helps maintain proper exhaust flow and ensures compliance with emissions standards.
Product Features & Benefits from Walker Products:
- Exact OE Fit: Direct-fit replacement designed for easy installation.
- OE Replacement Quality: Meets or exceeds original equipment specifications.
- Durable Design: Engineered to withstand high heat, vibration, and exhaust contaminants.
- Restores DPF Functionality: Provides accurate data for efficient DEF injection and filter regeneration.
- Aftermarket Expertise: Backed by over 75 years of experience in sensor manufacturing and engine management.
Symptoms of a Failing Differential Pressure Sensor:
- Engine will not start or starts poorly
- Detonation or misfire
- Excessive fuel consumption
- Reduced engine power or limp mode
- Check Engine Light illuminated
Common Check Engine Light (CEL) / OBD-II Codes
To reduce emissions, the EPA mandated OBD-II systems in all vehicles after 1996. This system standardizes diagnostics across all manufacturers.
The codes listed below are common for Differential Pressure Sensors and should be used as a general guide only. Walker Products will not be responsible for any use of this information. Always consult a qualified mechanic and follow manufacturer and EPA guidelines for diagnostics, replacements, and ECU/PCM relearn procedures.
- P0068 – MAP/MAF – Throttle Position Correlation
- P006A – MAP – Mass or Volume Air Flow Correlation
- P006B – MAP – Exhaust Pressure Correlation
- P006C – MAP – Turbocharger/Supercharger Inlet Pressure Correlation
- P00B8 – MAP – Mass or Volume Air Flow Correlation
- P0069 – Manifold Absolute Pressure – Barometric Pressure Correlation
- P0105 – Manifold Absolute Pressure/Barometric Pressure Circuit
- P0106 – Manifold Absolute Pressure/Barometric Pressure Circuit
- P0107 – Manifold Absolute Pressure/Barometric Pressure Circuit Low
- P0108 – Manifold Absolute Pressure/Barometric Pressure Circuit High
- P0109 – Manifold Absolute Pressure/Barometric Pressure Circuit Intermittent
- P023D – Manifold Absolute Pressure – Turbocharger/Supercharger Boost
- P023E – Manifold Absolute Pressure – Turbocharger/Supercharger Boost
- P2073 – Manifold Absolute Pressure/Mass Air Flow – Throttle Position
- P2074 – Manifold Absolute Pressure/Mass Air Flow – Throttle Position
- P2226 – Barometric Pressure Sensor “A” Circuit
- P2227 – Barometric Pressure Sensor “A” Circuit Range/Performance
- P2228 – Barometric Pressure Sensor “A” Circuit Low
- P2229 – Barometric Pressure Sensor “A” Circuit High
- P222A – Barometric Pressure Sensor “B” Circuit
- P222B – Barometric Pressure Sensor “B” Circuit Range/Performance
- P222C – Barometric Pressure Sensor “B” Circuit Low
- P222D – Barometric Pressure Sensor “B” Circuit High
- P222E – Barometric Pressure Sensor “B” Circuit Intermittent/Erratic
- P222F – Barometric Pressure Sensor “A”/“B” Correlation
- P2230 – Barometric Pressure Sensor “A” Circuit Intermittent/Erratic
- P2262 – Turbocharger/Supercharger Boost Pressure Not Detected
- P226B – Turbocharger/Supercharger Boost Pressure Too High – Mechanical