Faulty exhaust pressure sensor giving a falsely high signal; Wiring fault such as a short to the supply voltage or an open circuit on the signal or ground wire; Corroded, loose or damaged connector at the sensor or control unit; Blocked or restricted sensor pressure pipe, or a blocked exhaust component causing genuinely high pressure (such as a clogged particulate filter or catalyst); Faulty sensor reference supply or ground from the control unit; Internal fault in the engine control unit.

P0473

Exhaust Pressure Sensor A Circuit High.

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
73: FaultThe specific fault in that area

What it means

P0473 means the engine control unit has detected that the signal from exhaust pressure sensor A is higher than the expected range, which points to a high voltage condition in the sensor circuit. The fault is set when the signal stays above the calibrated limit for long enough, which can come from a short to voltage, an open ground, a faulty sensor or genuinely excessive exhaust pressure. The exact sensor position and strategy depend on the engine, so check the manufacturer data for your model.

Symptoms

Engine warning light on
Reduced power or the engine going into limp mode
Poor or hesitant acceleration
Turbocharger boost control issues such as overboost or underboost
Rough running or increased fuel consumption
Possible additional codes for the turbocharger, EGR or particulate filter

Possible causes

Faulty exhaust pressure sensor giving a falsely high signallikely
Wiring fault such as a short to the supply voltage or an open circuit on the signal or ground wirelikely
Corroded, loose or damaged connector at the sensor or control unitlikely
Blocked or restricted sensor pressure pipe, or a blocked exhaust component causing genuinely high pressure (such as a clogged particulate filter or catalyst)possible
Faulty sensor reference supply or ground from the control unitpossible
Internal fault in the engine control unitrare

How to diagnose

Read all stored and pending codes and note the freeze frame data, then look for related turbo, EGR or particulate filter codes.
Visually inspect the sensor, its pressure pipe and the wiring for heat damage, chafing, soot blockage or exhaust leaks.
Check the connector at the sensor and control unit for corrosion, bent pins, moisture or poor pin tension.
With the ignition on and engine off, view live exhaust pressure data; it should read close to ambient pressure, so compare against the manufacturer specification.
Measure the sensor reference supply, ground and signal voltage at the connector against the model's wiring diagram.
Check the signal wire for a short to voltage and for continuity back to the control unit with the connector disconnected.
Check the pressure pipe is clear and, if the reading is high with the engine running, assess for exhaust restriction such as a blocked filter or catalyst.
If the wiring and supplies are good, test or substitute the sensor following the manufacturer's procedure.

How to fix

Replace the exhaust pressure sensor if it reads incorrectly with good supply and wiring.
Repair or replace damaged wiring and fix any short to voltage or open circuit.
Clean, repair or replace the connector terminals if corroded or loose.
Clear or replace a blocked pressure pipe.
Correct the cause of any genuine exhaust restriction, such as a blocked particulate filter or catalyst, following the manufacturer's procedure.
Have the control unit checked and repaired or replaced only after all other causes are ruled out.

Can I keep driving?

Medium severity

The car can usually be driven carefully for a short time, but power may be limited and a genuine exhaust restriction or boost problem could cause damage. Get it diagnosed soon and avoid heavy loads or hard acceleration.

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