AdBlue Fault Codes Explained: P0470 P0472 & Solutions

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December 8, 2025

If your diesel shows P0470 or P0472, the AdBlue system is not reading exhaust pressure correctly. That single issue can trigger the AdBlue warning light, countdown messages and limp mode. You can fix these faults, but you need to know what each code means and where to start.

What P0470 and P0472 Actually Mean

Both codes point to a problem with the Exhaust Gas Pressure Sensor (EGPS).

  • P0470 → Exhaust pressure sensor circuit out of range.
  • P0472 → Exhaust pressure sensor signal too low.

This sensor helps the ECU monitor flow through the DPF and control AdBlue dosing. If the reading drops, spikes or disappears, the ECU cannot trust the data. That leads to:

  • AdBlue light
  • Reduced power
  • Incorrect NOx readings
  • DPF regeneration issues
  • Countdown to no-start on some vans

Common Causes

You are not dealing with one clear cause. Several things can trigger both codes.

  • Blocked pressure pipes
  • Split or cracked hoses
  • Water or soot contamination in the sensor
  • Failed EGPS sensor
  • Wiring damage
  • DPF pressure too high due to soot load
  • AdBlue build-up around the injector area affecting readings
  • Poor previous repairs

Think about recent work on the exhaust or DPF. That often leads to trapped moisture or kinked pipes.

Symptoms You Will Notice

You might see one or more:

  • AdBlue warning
  • Engine light
  • Reduced power
  • High fuel use
  • “Drive limited in X miles”
  • Forced limp mode
  • DPF regeneration not completing

If the countdown starts, act fast. Leaving the fault can lock the vehicle out from starting.

How to Fix P0470 & P0472

Start with simple checks before replacing parts. Most vans only need a pressure pipe clean or sensor swap.

1. Check the pressure pipes

Pull the rubber pipes off the DPF connection and sensor.

  • Look for soot
  • Check for blockages
  • Look for water in the hoses
  • Make sure the pipe has not softened or collapsed under heat

Replace if damaged. Clean if blocked.

2. Inspect the wiring

A torn sensor wire is common on vans used for site work.

Check for:

  • Rubbing points
  • Green corrosion
  • Loose connectors
  • Water inside the plug

Repair any broken sections.

3. Replace the Exhaust Gas Pressure Sensor

If readings are still out of range, the sensor is likely gone. A new sensor usually restores correct values straight away. After fitting, clear codes and check live data.

4. Check DPF backpressure

If backpressure is high, the sensor may only be reporting a deeper issue.

A blocked DPF changes pressure readings, which can trigger both codes. You may need a DPF clean, not a sensor.

Read more about our DPF cleaning service here:
DPF cleaning in Stoke-on-Trent.

5. Inspect AdBlue components

The pressure sensor is not part of the injector, but incorrect exhaust flow affects how AdBlue dosed gases move.

Check for:

  • Leaks around injector
  • Crystals on the injector body
  • Damage to the AdBlue pipe
  • NOx-related codes

If you also see NOx faults, review our main AdBlue solutions page:
AdBlue solutions service.

When These Codes Become Serious

If you ignore P0470 or P0472:

  • You risk no-start countdowns
  • You can fail an MOT
  • Fuel use rises
  • DPF damage becomes more likely
  • The AdBlue system may shut down completely

These faults create a chain reaction. Fixing them early saves money.

Vehicles We See These Faults On

You are likely dealing with one of these:

  • Ford Transit / Custom
  • Vauxhall Vivaro
  • Peugeot Boxer
  • Citroen Relay
  • Mercedes Sprinter
  • VW Crafter
  • Nissan NV400
  • Renault Master

Some of these vans run a strict countdown once the fault is active. Do not wait for that stage.

Why These Codes Often Return After DIY Fixes

You might clear the code and see it come back a day later. That is common.

Typical reasons:

  • The pressure hoses were not cleaned fully
  • Moisture left inside the sensor
  • High DPF backpressure
  • A cheap aftermarket sensor fitted
  • Wiring still damaged
  • AdBlue injector starting to crystallise

A proper diagnostic test stops you chasing the wrong part.

Book a full diagnostic session here:
Car diagnostics and servicing.

How Pro Remapping Fixes These Faults

You get a full step-by-step check:

  • Read all AdBlue, DPF and NOx codes
  • Live data review
  • Pressure pipe clean
  • Sensor testing
  • AdBlue injector test
  • DPF backpressure test
  • Road test and reset

If you need a sensor, we fit quality parts only.

If your DPF is blocked, we offer deep cleaning to bring it back within spec:
Professional DPF cleaning.

If NOx or AdBlue dosing faults are present, visit:
AdBlue repair service.

Work can be carried out mobile or in our workshop in Stoke-on-Trent. Service areas include Staffordshire, the Moorlands and Cheshire East.

FAQ

Why do P0470 and P0472 appear together?

Both use the same sensor, so when readings drop, both codes often set at the same time.

Can the van still be driven?

Yes, but power may be reduced. If a countdown appears, you must act quickly.

Will clearing the code fix it?

No. It only hides the problem for a short time.

Do I need a new DPF?

Not usually. A clean is often enough unless internal damage is present.

Can poor AdBlue quality trigger these codes?

Not directly, but poor dosing leads to NOx issues, which often sit alongside pressure faults.

Need a Fast Fix?

Book your AdBlue diagnosis today. We cover Stoke-on-Trent, Staffordshire, Cheshire East and the Moorlands.

Call: 074040 22260
Contact form: Get in touch with Pro Remapping

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