Faulty exhaust pressure sensor, for example contaminated with soot or failed internally; Damaged, chafed or corroded wiring to the sensor, including short or open circuit; Poor connection at the sensor or control unit plug, such as corrosion or loose terminals; Blocked, split or leaking pressure sensing pipe, where the sensor is remotely mounted; Exhaust leak near the sensor causing implausible readings; Fault in the sensor supply or reference voltage, or a shared ground problem; Faulty engine control unit.

P0470

Exhaust Pressure Sensor A Circuit.

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
70: FaultThe specific fault in that area

What it means

P0470 is the generic code for a fault in the exhaust pressure sensor 'A' circuit. The engine control unit monitors the sensor's signal voltage and sets the code when it is outside the expected range, stuck, or implausible compared with other readings such as engine load and airflow. The code points to the sensor circuit rather than proving the sensor itself has failed. Where the sensor sits and how it is used (for example turbo or particulate filter monitoring) depends on the engine.

Symptoms

Engine warning light on
Reduced power or limp mode
Poor or hesitant acceleration
Turbocharger boost control behaving oddly on turbocharged engines
Rough running or increased fuel consumption
Other exhaust or turbo related codes stored alongside

Possible causes

Faulty exhaust pressure sensor, for example contaminated with soot or failed internallylikely
Damaged, chafed or corroded wiring to the sensor, including short or open circuitlikely
Poor connection at the sensor or control unit plug, such as corrosion or loose terminalslikely
Blocked, split or leaking pressure sensing pipe, where the sensor is remotely mountedpossible
Exhaust leak near the sensor causing implausible readingspossible
Fault in the sensor supply or reference voltage, or a shared ground problemrare
Faulty engine control unitrare

How to diagnose

Read all stored and pending codes and note any related to turbo, boost, particulate filter or sensor supply voltage.
Review freeze frame data to see engine speed, load and temperature when the code set.
Visually inspect the sensor, its wiring and the connector for heat damage, chafing, corrosion, water or soot contamination.
Check for exhaust leaks around the sensor and any pressure pipe, and make sure the pipe is not blocked, split or loose.
With the ignition on, look at live exhaust pressure data and compare it with ambient pressure at key on and with expected change as revs rise.
Test the sensor supply, ground and signal wires for correct voltage and continuity against the manufacturer's wiring diagram.
Check the wiring for shorts to ground, shorts to voltage or high resistance, wiggling the harness while watching the live reading.
If wiring and supply are good, compare the sensor against the manufacturer's specification and replace it if it is out of range.

How to fix

Replace the exhaust pressure sensor if it is faulty or clogged beyond cleaning, following the manufacturer's procedure.
Repair or replace damaged wiring and fix any short or open circuit.
Clean, reseat or replace corroded or loose connector terminals.
Clear or replace a blocked or damaged pressure sensing pipe.
Repair any exhaust leak affecting the sensor reading.
Diagnose and repair the control unit or its supply only after all other causes are ruled out.

Can I keep driving?

Medium severity

The car can usually be driven for a short time, but it may go into limp mode and the underlying fault could affect exhaust or turbo control. Have it checked soon rather than leaving it.

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