Code P2452: particulate filter pressure sensor: circuit

Original definition (SAE J2012): Diesel Particulate Filter Pressure Sensor "A" Circuit^[1][2]

• P2452Diesel particulate filter pressure sensor "A" circuit.
• P2453Diesel particulate filter pressure sensor "A" circuit: range/performance (signal out of range or implausible). Ross-Tech lists it, on VAG cars, as an implausible signal from the filter's differential pressure sensor.^[6][11]
• P2454Diesel particulate filter pressure sensor "A" circuit: low signal.^[7]
• P2455Diesel particulate filter pressure sensor "A" circuit: high signal.^[8]

1. 1Faulty filter pressure sensor. This is the first cause on CarParts' list, Ross-Tech also includes it among the causes on VAG cars, and RACE counts a faulty differential pressure sensor among the usual faults of the emissions control system.^{[2][5][11][12]}
2. 2Blocked, loose or broken tubes or hoses carrying exhaust pressure to the sensor. Autobiz points out that, on these exhaust pressure sensors, the most common problem is carbon built up in the hollow bolt (banjo) or in the intake pipe, and Ross-Tech includes a restricted or blocked pipe among the causes of P2453.^[2][9][11]
3. 3Sensor wiring, connectors or fuse in poor condition. CarParts warns that wiring problems are among those that cause the most misdiagnoses, along with hoses.^[2][5][11]
4. 4Blocked particulate filter, or one with excess soot or ash.^[2]

• Engine warning light on.^[2]Engine warning light: faults that cause it
• Poorer engine performance.^[2]Less power: faults that cause it
• The car may enter limp mode, with power limited.^[2]Limp mode: faults that cause it
• Problems with the particulate filter's regeneration.^[2]

1. 1Start with a visual inspection of the sensor, its connector, the wiring and the sampling hoses: it is the cheapest check and, according to CarParts, where mechanics usually begin.^[2]
2. 2Check the sensor's fuse and electrical connections: Ross-Tech includes them among the causes of P2452 and P2453 on VAG cars.^[5][11]
3. 3Check that the sampling tubes are not blocked, loose or cracked. If there is carbon in the tube or in the hollow bolt, Autobiz suggests cleaning them by heating the pipe with an induction heater while blowing compressed air from the disconnected sensor side.^[2][9][11]
4. 4Consult the manufacturer's repair information and use a diagnostic scan tool to see the state of the sensor and the filter: CarParts insists that there is no one-size-fits-all fix for every car and that it is worth locating the cause before repairing.^[2]
5. 5If the tests point to a filter saturated with soot, that must be dealt with separately: a regeneration (sometimes forced at the workshop), a professional clean and, only if it does not recover, replacement of the filter.^[13]
6. 6Replace the sensor only if the earlier tests point to it: CarParts warns that replacing just the sensor does not always solve the fault, because the problem may be elsewhere in the circuit.^[2]