The P246D: Diesel Particulate Filter Pressure Sensor ‘A’/’B’ Correlation code indicates a discrepancy or lack of proper correlation between the readings of DPF pressure sensors ‘A’ and ‘B’. This could be due to faulty sensors, wiring problems, or connector issues that result in inconsistent pressure data, affecting the vehicle’s emissions control and the proper functioning of the DPF regeneration.
P246D – Quick Overview
Code | Information |
---|---|
Meaning | P246D: Diesel Particulate Filter Pressure Sensor ‘A’/’B’ Correlation |
Is it serious? | Moderate – correlation issues can lead to incorrect data for the DPF system, preventing proper regeneration and potentially causing filter clogging and increased emissions. |
Possible causes | – Correlation issues between pressure sensor ‘A’ and ‘B’ – Faulty sensors – Wiring or connector issues |
How to diagnose? | – Compare readings from pressure sensors ‘A’ and ‘B’ – Inspect and test the sensors and wiring – Replace faulty sensors or components if needed |
P246D Meaning
The P246D: Diesel Particulate Filter Pressure Sensor ‘A’/’B’ Correlation code indicates that there is a significant mismatch between the readings from DPF pressure sensors ‘A’ and ‘B’. These sensors are responsible for monitoring the pressure before and after the diesel particulate filter to determine its state of clogging and when regeneration is necessary. When the signals from these sensors do not match the expected correlation, it can prevent proper filter regeneration, leading to inefficient emissions control and increased exhaust backpressure.
Step-by-step diagnostic guide
Action | Description | Tools Needed |
---|---|---|
Check for Other Codes | Use an OBD-II scanner to determine if there are any additional fault codes. Related codes may provide further insight into the root cause of the correlation issue between pressure sensors. | OBD-II Scanner |
Compare Pressure Sensor Readings | Use a diagnostic tool to compare real-time readings from pressure sensors ‘A’ and ‘B’. The readings should have a consistent and expected relationship, especially during varying load conditions. | Diagnostic Tool |
Inspect the Sensors Visually | Visually inspect DPF pressure sensors ‘A’ and ‘B’ for any signs of physical damage, contamination, or improper installation. Make sure the sensors are securely mounted and in good condition. | Flashlight, Safety Gloves |
Test Sensors Individually | Test the output of each sensor using a multimeter. Verify that both sensors produce readings within the manufacturer’s specified range and respond similarly to changes in exhaust pressure. | Multimeter |
Inspect Wiring and Connectors | Inspect all wiring and connectors associated with pressure sensors ‘A’ and ‘B’. Look for any loose connections, damaged wires, or signs of corrosion that could lead to signal discrepancies. | Flashlight, Multimeter |
Check for Short or Open Circuits | Use a multimeter to test the continuity of the wiring connected to sensors ‘A’ and ‘B’. Verify that there are no shorts or open circuits that could cause inconsistent sensor signals. | Multimeter |
Repair or Replace Wiring and Connectors | If any damage is found in the wiring or connectors, repair or replace the affected components to ensure proper communication between the sensors and the engine control module. | Wiring Repair Kit, Connector Tools |
Replace Faulty Sensors | If one or both sensors are found to be faulty or if their readings do not align even after checking wiring and connectors, replace the sensors to restore correct pressure correlation. | Replacement Pressure Sensor, Wrench Set |
Clear the Code and Test Drive | After completing repairs, use an OBD-II scanner to clear the P246D code. Take the vehicle for a test drive and monitor both pressure sensors to verify that their readings now correlate properly. | OBD-II Scanner, Vehicle Owner’s Manual |
Recheck for Codes | Re-scan the vehicle after the test drive to confirm that the P246D code has not returned. If the code persists, further diagnostics may be required to identify any unresolved issues with the correlation. | OBD-II Scanner |

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Hi, I am Juraj “Yuri” Lukacko. I got frustrated by unhelpful and scammy mechanics, so I decided to learn everything about car diagnostics myself. I test dozens of new car diagnostic tools every month along with learning new strategies to fix and customize cars. About Juraj Lukacko (Yuri)