MasterTuning Fault code dictionary (DTC)

P20E8 — Reductant pressure too low

Severity: Serious Can you drive? With caution: limp mode possible, have it checked soon Make: All makes (OBD-II standard)
MeaningThe pump cannot bring AdBlue to the pressure required for injection. It is one of the faults that starts the countdown towards the no-start condition.
FamilyPowertrain (P)

Typical symptoms

AdBlue warning with remaining kilometres
Engine warning light on
Reduced power
Prolonged pump noise after switch-off

Common causes

AdBlue pump filter clogged with crystals
Worn pump
Blocked delivery line, or frozen in winter
Crystallised AdBlue injector
Non-compliant or aged fluid

What to do

Measure actual pressure on the diagnostic tool during a dosing cycle and inspect the filter: those two tests say whether the pump is recoverable. In winter rule out freezing first — below -11°C AdBlue freezes and the tank heater may not be working.

Frequently asked questions

What does code P20E8 mean?

Reductant pressure too low. The pump cannot bring AdBlue to the pressure required for injection. It is one of the faults that starts the countdown towards the no-start condition.

Can I keep driving with code P20E8 active?

With caution: limp mode possible, have it checked soon

Common causes — P20E8

AdBlue pump filter clogged with crystals Worn pump Blocked delivery line, or frozen in winter Crystallised AdBlue injector Non-compliant or aged fluid

How do you fix code P20E8?

Measure actual pressure on the diagnostic tool during a dosing cycle and inspect the filter: those two tests say whether the pump is recoverable. In winter rule out freezing first — below -11°C AdBlue freezes and the tank heater may not be working.

Need help with this fault?

We are ECU specialists: diagnosis, file repair and remapping for cars, bikes, trucks and agricultural vehicles.

Contact us
Where to get it fixed

Related codes