P0473
Exhaust Pressure Sensor A Circuit HighP0473 is a generic OBD-II powertrain diagnostic trouble code: Exhaust Pressure Sensor A Circuit High. 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 P0473 means
P0473 — Exhaust Pressure Sensor Circuit High — is the electrical complement to P0472. The ECM has detected a DPF differential pressure sensor output voltage above the maximum valid threshold. The indicated pressure is impossibly high — pegged at the top of the sensor's output range — and cannot be used for DPF regen control.
On a 0–5 V ratiometric sensor, a circuit-high fault typically means an open circuit in the signal return (ground) wire or sensor ground pin, allowing the signal rail to be pulled up to the reference voltage by the ECM's internal pull-up resistor. Alternatively, the signal wire may be shorted to the 5 V reference supply, or the sensor's internal bridge may have failed open on the ground side. On some sensors a broken internal element reads at maximum output because the bridge loses its ground reference.
The ECM's response to P0473 is the opposite of P0472: the default substituted pressure is interpreted as a heavily loaded or blocked DPF. Depending on platform, this may trigger immediate forced regen requests, persistent DPF warning lights, or limp mode — even though the filter's actual state may be perfectly fine. False regen events waste fuel, can overheat the DPF substrate if the actual soot load is low (uncontrolled high-temperature burn), and may lead to unnecessary DPF replacement. The sensor-high fault is therefore potentially more immediately disruptive than the sensor-low fault.
Common causes
Most-frequently reported root causes when P0473 is logged.
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1
Open circuit in the sensor signal ground or sensor negative reference wire — most common cause; the floating ground pulls the signal high via the ECM's internal pull-up.
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2
Signal wire shorted to the 5 V sensor supply line.
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3
Internal open circuit within the sensor's sensing element or bridge circuit.
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4
Backed-out or corroded ground pin at the sensor connector.
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5
Broken sensor wiring harness near the exhaust — heat damage that opens the ground wire is common.
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6
ECM internal fault causing the input to read at its maximum rail (rare).
Symptoms drivers notice
How to diagnose P0473
A typical diagnostic flow when this code is present.
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1
With KOEO, measure the sensor signal voltage at the connector with the sensor connected — at or near 5 V confirms the signal is being pulled high.
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2
Disconnect the sensor and measure signal voltage again — if it drops close to 0 V after disconnection, the sensor's internal element is failed high (open ground side); if it remains near 5 V with sensor disconnected, the signal wire is shorted to the supply.
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3
Measure continuity from the sensor ground pin on the harness side to chassis ground — infinite resistance confirms an open ground wire; trace and repair.
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4
Inspect the sensor connector for backed-out ground pin, corrosion, or heat damage — common where the harness passes close to the DPF or exhaust manifold.
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5
Inspect the harness for heat-damaged sections near the exhaust routing.
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6
If wiring checks out, replace the sensor — confirm with a 0 V signal reading at ambient (engine cold) after installation.
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7
After repair, clear codes, verify the dP PID reads near-zero at idle, and force a regen via scan tool to confirm the full dP response cycle.
Vehicles where we've handled P0473
Platforms in our catalogue with confirmed P0473 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
Why is P0473 potentially more urgent than P0472?
P0472 (signal low) causes the ECM to think the DPF is clean and skip regens — the filter fills slowly over time. P0473 (signal high) causes the ECM to think the DPF is critically blocked and may immediately trigger forced regens, limp mode, or DPF replacement warnings. False regens on a lightly loaded DPF can drive substrate temperatures high enough to cause thermal damage. Address P0473 before the next drive if possible.
Can P0473 be caused by an exhaust system that is genuinely blocked?
Yes — if the DPF is severely and physically blocked, the actual differential pressure across it can be so high that it exceeds the sensor's rated maximum range and the output saturates at maximum voltage, which the ECM then flags as P0473. In this case the code is accurate and the DPF requires forced regen, cleaning, or replacement. Check whether the code appeared suddenly after prolonged low-speed city driving without a regen opportunity, or after a failed regen event.
What is the typical dP sensor output at a clean DPF idle?
On most light-duty diesel applications, a clean DPF at warm idle will show 0–10 mbar differential pressure (sensor output approximately 0.5–1.0 V on a 0–5 V ratiometric sensor). At motorway cruise on a partially loaded DPF, values of 20–80 mbar are typical. Values above 200 mbar at idle indicate severe DPF blockage; values at or above the sensor's full-scale output (e.g. > 4.8 V on a 5 V sensor) indicate either a P0473 electrical fault or a catastrophically blocked filter.
Disabling P0473 in software
RaceTune can permanently disable P0473 — 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 P0473 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 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.
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