P0472 indicates that the powertrain control module has detected a voltage signal from the exhaust pressure sensor that is lower than the calibrated acceptable range. This typically means the sensor, its wiring, or a connector is causing the circuit to read near zero volts. The code is electrical in nature and does not indicate a mechanical exhaust blockage.
The sensor’s internal circuitry can fail or short, causing it to output a voltage near zero and trigger a circuit-low reading regardless of actual exhaust pressure.
Chafed, pinched, or damaged wiring can allow the sensor signal circuit to contact the chassis or another ground source, pulling the voltage seen by the PCM below threshold.
Moisture, salt, or oil intrusion at the connector can bridge terminals and effectively short the signal circuit to ground or disrupt the reference voltage.
A loss of the 5-volt reference supply—whether from an open wire or a short to ground—can prevent the sensor from generating a valid output signal.
Although uncommon, a rare internal failure within the PCM can misinterpret a normal sensor voltage as being too low; this should only be considered after wiring and sensor integrity are confirmed.
Almost never. This code is almost always caused by a failed exhaust pressure sensor, a wiring short to ground, or connector corrosion. PCM failure is a rare cause for a circuit-low fault and should only be suspected after the sensor and entire harness have been electrically verified as good.
Limited driving is usually possible, but the engine may run in a reduced-power limp mode and produce higher emissions. Prolonged operation risks damaging exhaust aftertreatment components, so repair should not be delayed.
No. P0472 is strictly an electrical circuit fault indicating voltage is too low. A physical restriction raises pressure and would typically set a performance or rationality code rather than a circuit-low code.
Disconnect the sensor and measure the signal circuit voltage. If it remains near zero with the sensor unplugged, the wiring is likely shorted to ground. If the voltage returns to a normal open-circuit or reference level, the sensor itself is probably faulty.