Faulty exhaust pressure sensor; Damaged or disconnected sensor wiring or connector; Clogged or restricted exhaust pressure sensor tube or port; Exhaust leaks upstream of the sensor; Corroded or poor electrical connections at the sensor or PCM; Failed PCM (rare)

DTC codes / P04xx · Auxiliary emission controls / P0472

P0472Exhaust Pressure Sensor Low

Q: What does code P0472 mean?

Exhaust Pressure Sensor Low. P0472 means the powertrain control module (PCM) has detected a low voltage signal from the exhaust pressure sensor circuit, indicating the sensor reading is below the expected range for current operating conditions. The computer compares the sensor signal to a calculated model and sets this code when the voltage stays too low for a calibrated time.

P0472 means the powertrain control module (PCM) has detected a low voltage signal from the exhaust pressure sensor circuit, indicating the sensor reading is below the expected range for current operating conditions. The computer compares the sensor signal to a calculated model and sets this code when the voltage stays too low for a calibrated time.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaAuxiliary emission controls

Symptoms you may notice

Illumination of the check engine light, often with no other noticeable symptoms
Reduced engine power or limp mode in some vehicles
Poor fuel economy or increased regeneration frequency on diesel engines
Black smoke or excessive exhaust smoke under load
Rough running or hesitation during acceleration
Failed emissions test due to incomplete readiness monitors

Common causes, most likely first

Faulty exhaust pressure sensor
Damaged or disconnected sensor wiring or connector
Clogged or restricted exhaust pressure sensor tube or port
Exhaust leaks upstream of the sensor
Corroded or poor electrical connections at the sensor or PCM
Failed PCM (rare)

How to diagnose and fix it

Inspect the sensor and its wiring for physical damage, corrosion, or loose connections
Check the sensor tube and port for blockage or carbon buildup and clean if necessary
Measure reference voltage and ground at the sensor connector with a multimeter
Compare sensor live data to expected values or a known-good sensor
Perform a voltage drop test on the signal circuit to rule out high resistance
Replace the exhaust pressure sensor if tests confirm it is faulty
Clear the code and verify repair with a test drive and monitor readiness

Common misdiagnosis traps for P0472

A clogged sensor tube often mimics a failed sensor, so always check for blockage before replacing parts.
Exhaust leaks upstream of the sensor can cause low pressure readings and set this code, yet are frequently overlooked.
The sensor may test good statically but fail under heat and vibration, so wiggle-test wiring while monitoring live data.
On some vehicles, a low exhaust pressure reading can be caused by a restricted diesel particulate filter (DPF) rather than the sensor itself.
This code does not always indicate a sensor failure; circuit issues or mechanical restrictions are equally common causes.

Can I keep driving with P0472?

You can usually drive with this code, but avoid heavy acceleration or towing until diagnosed, as the engine may enter limp mode or regeneration may be inhibited, potentially leading to further damage.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.