Emissions

P0472 — Exhaust Pressure Sensor Circuit Low

Severity: medium Drive with care, to a shop

What P0472 means

The engine control module constantly monitors the exhaust pressure sensor, which outputs a voltage proportional to pressure in the exhaust. The ECM uses it to judge diesel particulate filter loading and turbo behavior. P0472 sets when that voltage falls below the expected range, most often from a short to ground or a failed sensor.

Symptoms

  • Check engine light on
  • False DPF-related codes
  • Reduced power or limp mode
  • Failed or incomplete DPF regeneration
  • Higher fuel consumption

Possible causes

  1. Signal wire shorted to ground
  2. Failed exhaust pressure sensor
  3. Corroded or damaged connector at the sensor near the DPF
  4. Chafed or damaged wiring harness near the exhaust
  5. Open or shorted reference voltage supply
  6. Faulty ECM (rare)

How to diagnose

  1. Scan all codes and freeze frame data, noting any DPF codes
  2. Inspect the sensor connector and harness for chafing, moisture, corrosion, and heat damage
  3. Check the sensor's pressure line for clogging or damage
  4. With the engine off, compare the sensor reading to ambient pressure on a scan tool
  5. Use a multimeter to check for 5 V reference and ground at the sensor connector
  6. Unplug the sensor and test the signal wire for a short to ground
  7. If wiring is good, replace the sensor, clear the code and see if it returns

Common fixes

  • Replace the exhaust pressure sensor
  • Repair or replace damaged wiring
  • Clean or replace the corroded connector
  • Replace or clear the sensor's pressure line
  • Diagnose and replace the ECM only if all circuits test good

Questions and answers

What does P0472 mean?

It means the ECM detected low voltage in the exhaust pressure sensor circuit. A short to ground in the wiring or a bad sensor is the most common cause.

Can I drive with P0472?

Briefly and carefully, yes, but don't put it off. Without good pressure data, DPF regeneration may not work properly, which can lead to costly damage.

Can P0472 cause DPF codes?

Yes. The ECM relies on this sensor to estimate filter loading, so false DPF codes often appear. They usually clear once the P0472 cause is fixed.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.