Faulty exhaust pressure sensor giving a low output; Damaged, chafed or heat-affected wiring shorted to ground or open circuit in the signal or supply wire; Corroded, loose or contaminated connector terminals at the sensor or control unit; Blocked, sooted or disconnected sensor pressure pipe or hose, where the sensor is remote-mounted; Loss of the sensor's 5 V reference supply or a poor ground from a fault elsewhere on the shared circuit; Fault inside the engine control unit.

P0472

Exhaust Pressure Sensor A Circuit Low.

Generic
Powertrain
Generic code
Medium severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
4: AreaAuxiliary emission controls
72: FaultThe specific fault in that area

What it means

P0472 is the generic code for Exhaust Pressure Sensor A Circuit Low. The engine control unit monitors the signal voltage from the exhaust pressure sensor and has seen it fall below the expected range, typically close to 0 V, which suggests a short to ground, an open circuit or a failed sensor. The exact sensor location and the way the reading is used depend on the engine, as it is commonly fitted to turbocharged and diesel engines.

Symptoms

Engine warning light on
Reduced power or limp mode
Poor turbocharger boost control or inconsistent boost
Black or excess smoke from the exhaust on some engines
Rough running or hesitation under load
Failed or delayed particulate filter regeneration on some diesel engines

Possible causes

Faulty exhaust pressure sensor giving a low outputlikely
Damaged, chafed or heat-affected wiring shorted to ground or open circuit in the signal or supply wirelikely
Corroded, loose or contaminated connector terminals at the sensor or control unitlikely
Blocked, sooted or disconnected sensor pressure pipe or hose, where the sensor is remote-mountedpossible
Loss of the sensor's 5 V reference supply or a poor ground from a fault elsewhere on the shared circuitpossible
Fault inside the engine control unitrare

How to diagnose

Read all stored and pending codes and note any other sensor supply or exhaust related faults, then check freeze frame data for conditions when the fault set.
Inspect the sensor, its connector and the wiring run for heat damage, chafing, oil contamination, corrosion and bent or pushed-back terminals.
View live data for the exhaust pressure reading with the engine off and then running, and compare it with the expected ambient pressure and with the manufacturer's specification for the engine.
Check the sensor's 5 V reference supply, ground and signal voltage at the connector with a multimeter, following the wiring diagram for the model.
Wiggle-test the harness and connector with the engine running or the ignition on to see whether the reading changes or the fault returns.
Test the signal wire for a short to ground and for continuity back to the control unit with the connector unplugged and the ignition off.
If the sensor uses a pressure pipe, check the pipe for blockage, cracks and secure connections.
Check whether a software update or technical bulletin exists for the engine, as procedures vary by model.

How to fix

Replace the exhaust pressure sensor if it fails the signal or live data checks.
Repair or replace damaged wiring or the affected section of the harness, using proper soldered or crimped weatherproof joints.
Clean or replace corroded connector terminals and ensure the connector locks securely.
Clear or replace a blocked, cracked or disconnected pressure pipe.
Restore a faulty reference supply or ground by repairing the shared circuit, and clear the codes then road test to confirm the fault does not return.

Can I keep driving?

Medium severity

The car can usually be driven short distances, but it may go into limp mode and the exhaust and boost control may not work correctly. Have it checked soon, as prolonged driving with incorrect boost control or filter regeneration can lead to further damage.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.