P2452: Diesel Particulate Filter Pressure Sensor A Circuit

What does P2452 mean?

The pressure sensor A of the particulate filter, usually a differential sensor with hoses to the filter inlet and outlet, tells the ECM how loaded the filter is. Despite its generic circuit title, P2452 is in practice an offset check made when no exhaust flows. Ford's 2023 diesels run it in after-run and set the code when the sensor still reads more than 1 kPa. GM's 2018 diesels check the filter inlet pressure at the start of the drive cycle, after at least 10 s engine off, and set it as a Type B code when the offset is too big. A sensor that has drifted, moisture inside it or a hose holding pressure all give such an offset. Audi saw P2452 together with P2453, P2454, P2456 and P2002 on the 2009 to 2011 Q7 TDI and traced it to moisture entering the differential pressure sensor G505 through poor internal sealing; the fix was a sensor with better sealing. The soot model then works with wrong values, so regeneration timing suffers.

The code tells you which monitor failed, not which part is broken. Test before replacing parts.

Symptoms

• Malfunction indicator lamp on
• Regeneration too early, too late or inhibited

Common causes

• High Sensor offset drifted or moisture inside the sensor
• Medium Sensor hose blocked by soot or condensate
• Low Corroded connector or terminals

Likelihood is a general estimate across vehicles; your make and model may differ.