P0470
Exhaust Pressure Sensor A CircuitP0470 is a generic OBD-II powertrain diagnostic trouble code: Exhaust Pressure Sensor A Circuit. 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 P0470 means
P0470 — Exhaust Pressure Sensor Malfunction — is the generic entry-point fault for the differential pressure sensor circuit that measures exhaust back pressure across the Diesel Particulate Filter (DPF). Unlike P0471–P0473 which classify the failure as a rationality, low, or high sub-fault, P0470 indicates a general circuit malfunction: the PCM has detected that the sensor signal is absent, implausible, or has failed to respond in a way consistent with any single specific electrical sub-fault classification.
The exhaust differential pressure (dP) sensor — sometimes called the DPF dP sensor or exhaust back-pressure (EBP) sensor — is a small differential pressure transducer with two sampling ports. The high-pressure port connects upstream of the DPF via a stainless steel tube; the low-pressure port connects downstream (or to atmosphere in some designs). The voltage output changes proportionally to the pressure difference across the filter, giving the ECM a real-time measure of soot loading. This signal is central to DPF regeneration logic: the ECM initiates active regen when the dP rises above a calibrated soot-load threshold, and terminates regen when dP falls back to a clean-filter baseline.
When P0470 is set, the ECM loses this feedback and typically substitutes a fixed default pressure value. The consequence is degraded regen control: regens may be triggered at the wrong time, fail to complete, or not trigger at all — leading progressively to DPF overfill, forced DPF replacement, or a permanent ash-load fault. Repair priority is high on diesel vehicles.
Common causes
Most-frequently reported root causes when P0470 is logged.
-
1
Failed differential pressure sensor (internal element failure — most common cause).
-
2
Blocked or clogged high-pressure sampling tube between the exhaust manifold/upstream DPF port and the sensor — soot, condensed oil, or carbon can fully obstruct the tube.
-
3
Cracked, disconnected, or melted high- or low-pressure sampling tube.
-
4
Corroded or damaged wiring connector at the sensor.
-
5
Open or short circuit in the sensor signal, reference voltage, or ground wire.
-
6
DPF itself severely blocked, generating pressure excursions that exceed the sensor's rated input range and damage the sensing element.
-
7
PCM internal fault causing incorrect voltage interpretation (rare).
Symptoms drivers notice
How to diagnose P0470
A typical diagnostic flow when this code is present.
-
1
Read all DTCs and note any companion DPF, EGR, or exhaust temperature codes that indicate a systemic exhaust system issue.
-
2
Inspect the high- and low-pressure sampling tubes from the DPF ports to the sensor for blockage, cracks, kinks, or disconnection — blow through with compressed air to confirm clear passage.
-
3
Inspect the sensor electrical connector for corrosion, moisture, or broken pins.
-
4
With KOEO, measure the sensor reference voltage (typically 5 V) and ground at the connector using a multimeter; missing reference or ground confirms a wiring fault.
-
5
With the engine running, observe the sensor output PID on a scan tool — at idle the dP should read near zero (0–5 mbar); a reading pegged at zero, maximum, or erratically jumping confirms sensor or tube fault.
-
6
Disconnect the high-pressure tube at the sensor and briefly apply gentle mouth pressure — a good sensor will show a live dP rise on the scan tool.
-
7
Replace sensor if tubes and wiring check out; clear codes and perform a DPF regen test drive to verify restoration of regen logic.
Vehicles where we've handled P0470
Platforms in our catalogue with confirmed P0470 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
What is the DPF dP sensor and why is it important?
The differential pressure (dP) sensor measures the pressure drop across the DPF by comparing upstream and downstream exhaust pressures. As soot accumulates in the DPF, flow resistance increases and the pressure difference grows. The ECM monitors this value to decide when to initiate and terminate active regeneration. Without it, the ECM cannot accurately determine soot loading and DPF management is effectively blind.
Can I clear P0470 and keep driving?
On a diesel, no — not for more than a short drive to a workshop. Without accurate dP feedback, regens either fail to trigger (allowing soot to accumulate until the DPF is damaged) or trigger incorrectly. An overfilled DPF that undergoes an uncontrolled regen can reach temperatures that damage the filter or surrounding components. Repair promptly.
Is the sampling tube often the real culprit?
Yes — a blocked sampling tube is the single most common cause of P0470 and P0471 on high-mileage diesel vehicles. Oil mist and soot gradually fill the small-bore metal tube, stopping pressure from reaching the sensor. The sensor itself is fine but reads zero because no pressure variation is transmitted. Always check the tubes before replacing the sensor.
Disabling P0470 in software
RaceTune can permanently disable P0470 — 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 P0470 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 EDC17C74 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 P0470 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