P24A5
Particulate Filter Differential Pressure Sensor Circuit Range/PerformanceP24A5 is a generic OBD-II powertrain diagnostic trouble code: Particulate Filter Differential Pressure Sensor Circuit Range/Performance. It is logged by the engine control unit when the powertrain monitor detects that a specific fault threshold has been exceeded — typically resulting in the malfunction-indicator lamp (MIL / check-engine light) being illuminated.
What P24A5 means
P24A5 indicates that the ECM has detected a signal from the diesel particulate filter differential pressure sensor that is within the electrical operating range but does not match expected values based on current engine operating conditions. This is a rationality or performance fault rather than an open/short circuit fault.
The differential pressure sensor measures the pressure drop across the DPF to estimate soot loading. When the measured differential pressure is inconsistent with the calculated soot model or exhaust flow conditions, the ECM flags a performance concern. This can be caused by a partially blocked sensor port, contaminated sensor, or a sensor that has drifted out of calibration.
Because the ECM relies on this sensor to trigger and monitor DPF regeneration, a faulty reading can result in missed regenerations, premature regeneration attempts, or an inaccurate soot-load estimate. Prompt diagnosis helps prevent unnecessary DPF damage or unnecessary regeneration cycles.
Common causes
Most-frequently reported root causes when P24A5 is logged.
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1
DPF differential pressure sensor partially blocked by soot or condensation giving a biased reading.
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2
Cracked, kinked, or partially obstructed pressure sensor sampling hoses.
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3
Sensor output has drifted out of the expected calibration range due to age or contamination.
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4
Air leak in the exhaust system upstream or downstream of the DPF altering the differential pressure.
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5
DPF partially blocked causing an abnormally high differential pressure that falls outside plausibility limits.
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6
Wiring harness damage causing intermittent signal corruption without a full open or short circuit.
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7
ECM software fault or incorrect sensor calibration offset stored in memory.
Symptoms drivers notice
How to diagnose P24A5
A typical diagnostic flow when this code is present.
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1
Read and record all DTCs and freeze-frame data with a scan tool.
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2
Inspect the DPF differential pressure sensor hoses for blockages, cracks, or disconnections.
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3
Monitor differential pressure live data at idle and compare to expected values for a warm engine at idle.
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4
Check sensor reference voltage and ground at the sensor connector using a multimeter.
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5
Clear the blockage from sensor sampling hoses if found and retest sensor output.
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6
Replace the differential pressure sensor if hoses are clear and the signal remains out of range.
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7
Recheck for DTCs after repair and verify sensor readings match expected values across the engine speed range.
Vehicles where we've handled P24A5
Platforms in our catalogue with confirmed P24A5 coverage.
Related powertrain codes
- P2400 — Evaporative Emission System Leak Detection Pump Control Circuit/Open
- P2401 — Evaporative Emission System Leak Detection Pump Control Circuit Low
- P2402 — Evaporative Emission System Leak Detection Pump Control Circuit High
- P2404 — EVAP Leak Detection Pump Sense Circuit: Implausible Signal
- P2405 — Evaporative Emission System Leak Detection Pump Sense Circuit Low
- P2407 — Evaporative Emission System Leak Detection Pump Sense Circuit Intermittent/Erratic
Frequently asked questions
Is P24A5 the same as a completely failed pressure sensor?
No. P24A5 is a rationality fault meaning the sensor signal is electrically valid but implausible. A completely failed sensor would typically set an open or short circuit code instead.
Can blocked sensor hoses cause this code?
Yes. Partially blocked hoses are one of the most common causes of a differential pressure performance fault and should be inspected first.
Does P24A5 mean my DPF needs replacing?
Not necessarily. The code is more commonly caused by sensor or hose issues. DPF replacement is only warranted if the filter itself is confirmed to be faulty after sensor issues are ruled out.
How do I unblock DPF pressure sensor hoses?
Carefully disconnect the hoses from the sensor and DPF ports, then blow compressed air through them to clear any soot or condensation. Inspect the port openings on the DPF for blockage as well.
Disabling P24A5 in software
RaceTune can permanently disable P24A5 — and any other OBD-II diagnostic trouble code — on every ECU family we support. The monitor is disabled inside the ECU itself, so the fault stops being logged: the warning light stays off and the engine never enters limp mode for this code. The change is tied to your exact software version.
ECUs with a P24A5 disable in our catalogue
Confirmed coverage from our recipe database — we support many more families. Upload your file and our identifier will match it automatically.
- Bosch EDC17C50 verified 1 software version
Software modifications affect emissions compliance and are not road-legal in many jurisdictions. RaceTune service files are intended for motorsport, off-road, and export use.
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