P0472
Exhaust Pressure Sensor A Circuit LowP0472 is a generic OBD-II powertrain diagnostic trouble code: Exhaust Pressure Sensor A Circuit Low. 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 P0472 means
P0472 — Exhaust Pressure Sensor Circuit Low — is set when the PCM/ECM detects that the DPF differential pressure sensor signal voltage has fallen below the minimum valid threshold. This is a hard electrical low fault: the indicated pressure is impossibly low (pegged at zero or below the sensor's minimum output floor), and the ECM cannot use the value for DPF regen control.
On a standard 0–5 V ratiometric pressure sensor, a low circuit fault typically means the signal wire is shorted to ground, the sensor's internal resistive bridge has failed with a short, or the sensor power supply (5 V reference) is missing, causing the signal to pull to ground. Some designs use a 4–20 mA current-loop output; a low fault on these types indicates an open in the current path rather than a voltage short.
The ECM's response to P0472 is to substitute a default rest-state pressure value — typically the clean-filter baseline pressure. This means the ECM believes the DPF is perpetually clean and never initiates an active regen based on soot-load dP threshold. Over time, soot accumulates without a regen being triggered, and the DPF becomes progressively over-saturated. On vehicles with passive regen (motorway driving) some soot burns passively, but without active regen management the DPF will eventually reach an ash or soot load that requires forced regen or physical cleaning. Priority repair on any diesel with a DPF.
Common causes
Most-frequently reported root causes when P0472 is logged.
-
1
Signal wire shorted to chassis ground between the sensor connector and the ECM.
-
2
Internal short within the sensor's pressure-sensing element or Wheatstone bridge circuitry.
-
3
Loss of 5 V sensor reference supply — if the reference wire is open or the reference supply fuse is blown, the signal rail collapses to zero.
-
4
Moisture or oil contamination inside the sensor connector creating a low-resistance path to ground.
-
5
Chafed signal wire contacting the exhaust pipe, chassis, or other grounded metal.
-
6
Failed ECM input pin with an internal short pulling the signal low (rare).
Symptoms drivers notice
How to diagnose P0472
A typical diagnostic flow when this code is present.
-
1
With KOEO, measure the sensor reference voltage (pin 1 or supply pin per wiring diagram) at the sensor connector — should be ~5 V; zero confirms a missing supply (check fuse and reference wire).
-
2
Measure signal voltage at the signal pin with the sensor connected — near-zero confirms the signal is pulled low; disconnect the sensor and if the signal pin rises towards 5 V, the sensor is internally shorted.
-
3
With the sensor disconnected, measure resistance from the signal wire to chassis ground from the harness side — low resistance (< 1 kΩ) confirms a wire-to-ground short; trace and repair.
-
4
Inspect the sensor connector for oil or moisture ingress and clean with electrical contact cleaner.
-
5
Inspect the signal wire routing along the exhaust/chassis for chafing points.
-
6
Replace sensor if internal short is confirmed after wiring checks are clear.
-
7
After repair, force a DPF regen via scan tool and verify the dP PID rises and falls correctly through the regen event.
Vehicles where we've handled P0472
Platforms in our catalogue with confirmed P0472 coverage.
Related powertrain codes
- P0400 — Exhaust Gas Recirculation Flow Malfunction
- P0401 — Exhaust Gas Recirculation Flow Insufficient Detected
- P0402 — Exhaust Gas Recirculation Flow Excessive Detected
- P0403 — Exhaust Gas Recirculation Circuit Malfunction
- P0404 — Exhaust Gas Recirculation Circuit Range/Performance
- P0405 — Exhaust Gas Recirculation Sensor A Circuit Low
Frequently asked questions
Will the ECM attempt any regen at all with P0472 set?
On most platforms, no active regen will trigger via the soot-load dP threshold because the ECM reads a flat-zero dP and concludes the DPF is clean. Some ECMs also run a time-based regen fallback strategy (regen every N hours of engine run time regardless of dP), which partially mitigates the risk — but this is a coarse fallback, not a substitute for proper dP feedback. Check the specific platform's DPF degraded-mode strategy.
How do I tell if the sensor is shorted internally vs. the wiring?
Disconnect the sensor from the harness. Measure the signal wire at the harness connector to chassis ground — if resistance is low with the sensor disconnected, the short is in the wiring. If resistance is high with the sensor disconnected but the signal read low when the sensor was connected, the sensor element itself is shorted internally.
Disabling P0472 in software
RaceTune can permanently disable P0472 — 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 P0472 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
- Bosch EDC17C74 verified 1 software version
- Bosch EDC17CP09 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.
Got P0472 in your scan?
Upload your ECU file — we'll identify the exact software version and confirm whether a disable is available for your car.
Upload your file