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P0470 – Exhaust Pressure Sensor Malfunction (OBD2)

P0470 means "Exhaust Pressure Sensor Malfunction". The control unit has detected a fault in the electrical circuit of the exhaust back pressure sensor / control valve: the signal or control current is missing or outside the expected window. The code does not say whether the value is too high or too low, so the wiring and the component itself both have to be checked.

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P0470 quick summary

Fault codeP0470
MeaningExhaust Pressure Sensor Malfunction
SystemPowertrain (Engine & Transmission)
VehiclesGeneric OBD2
SeverityMedium
Can I drive?Usually yes, gently, but expect reduced power or limp mode. Have it checked soon.
Repair cost€30 – €600

How the exhaust pressure sensor and control valve work

Diesel engines use an exhaust pressure sensor and sometimes an exhaust pressure control valve (exhaust brake/flap) to monitor and control back pressure for EGR, DPF and warm-up.

The exhaust back pressure sensor measures pressure in the exhaust manifold or before the turbocharger. The control unit uses it for EGR control, turbo control and to detect blockages. An exhaust pressure control valve (exhaust flap) can be closed to raise back pressure – for faster warm-up, more EGR or an exhaust brake on commercial vehicles.

Codes P0470–P0474 cover the sensor and P0475–P0479 the control valve. The sensor port and its pipe are exposed to soot and condensation, so blockages and cracked pipes are common causes besides electrical faults.

A wrong back pressure reading can cause limp mode, incorrect EGR operation and turbo control problems; a stuck flap reduces power and raises exhaust temperatures.

On VAG vehicles (VW, Audi, Škoda, Seat, Cupra), VCDS and older VAG testers can show this code as the five-digit VAG code 16854 (P0470). Both numbers mean the same fault.

Symptoms of P0470

  • Check Engine light on
  • Reduced power or limp mode
  • Turbo or EGR related codes
  • Black smoke
  • Slow warm-up (stuck exhaust flap)

Most common causes of P0470 (most likely first)

Mechanic's Pro Tip

Most exhaust pressure sensor codes on diesels are not the sensor but the small steel or silicone pipe to it – blocked with soot or cracked. Clean it before buying a sensor.

  1. 1.Damaged wire or loose, corroded connector at the exhaust back pressure sensor / control valve

    Most likely

    Green or white corrosion, pushed-back pins and chafed insulation near hot or moving parts are the most common findings.

  2. 2.Faulty exhaust back pressure sensor / control valve

    An internal break or short in the component itself.

  3. 3.Blown fuse or missing supply voltage

    If several codes appeared at the same time, check the shared fuse, relay or ground point first.

  4. 4.Blocked sensor pipe or port (soot, condensation)

  5. 5.Cracked or disconnected sensor pipe

  6. 6.Sticking exhaust pressure control valve or actuator

Step-by-step diagnostic guide

  1. 1

    Read codes and pressure values

    Read all codes and check the exhaust pressure value with the engine off (should equal atmospheric pressure) and when revving.

  2. 2

    Check the circuit with a multimeter

    With the ignition off, unplug the exhaust back pressure sensor / control valve and the control unit connector (or back-probe), then check each wire between them for continuity and for shorts to ground and to battery voltage. Compare the component's resistance or supply voltage with the value in the repair manual.

    Multimeter: Wire continuity: below about 1 Ω. Wire to ground with both connectors unplugged: no continuity. Supply/reference with ignition on: usually 5 V for sensors, battery voltage for actuators.

  3. 3

    Check the sensor pipe

    Remove and clean the pipe and port; check for cracks and correct routing.

  4. 4

    Check the sensor electrically

    Measure 5 V reference, ground and signal at the connector.

    Multimeter: Key on, engine off: reading close to barometric pressure.

  5. 5

    Test the control valve

    Command the valve with the scan tool and check that it moves freely; check its vacuum supply or electrical actuator.

  6. 6

    Replace and verify

    Replace the faulty part, clear codes and check readings on a test drive.

Frequently asked questions

Can I keep driving with P0470?

Usually yes, gently, but expect reduced power or limp mode. Have it checked soon.

How much does it cost to fix P0470?

Typical repair costs are 30 € – 600 €, depending on the cause and the vehicle. The most common fixes are: damaged wire or loose, corroded connector at the exhaust back pressure sensor / control valve; faulty exhaust back pressure sensor / control valve; blown fuse or missing supply voltage. Always confirm the cause with the tests above before buying parts.

What does the exhaust pressure sensor do?

It measures back pressure in the exhaust, which the control unit uses for EGR and turbo control and to detect blockages.

Is it the same as the DPF differential pressure sensor?

No. The DPF sensor measures the pressure difference across the particulate filter; the exhaust pressure sensor measures absolute pressure before the turbo or in the manifold.

What is the difference between P0470 and similar codes?

P0470 belongs to a group of codes for the same component that differ in the type or location of the fault: P0471 – Exhaust Pressure Sensor Range/Performance; P0472 – Exhaust Pressure Sensor Low; P0473 – Exhaust Pressure Sensor High; P0474 – Exhaust Pressure Sensor Intermittent; P0475 – Exhaust Pressure Control Valve Malfunction; P0476 – Exhaust Pressure Control Valve Range/Performance. The tests on this page apply to the whole group; the type of fault tells you where to start.

Related fault codes

This guide is for information only. Working on vehicles can be dangerous — if you are unsure, have the car checked by a qualified mechanic. Values can differ between model years; always check the manufacturer's repair information.