P20E2
Reductant Pressure Too High
The reductant line pressure exceeds the upper limit. A blocked return path, a stuck pump or a faulty pressure sensor are common causes; over-pressure can damage the dosing valve and the pump head.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Symptoms
- Check engine light or NOx warning on
- AdBlue/DEF level or quality warning
- Possible no-start countdown after ignore period
- Failed emissions inspection (NOx)
Common causes
Ordered by how often each turns out to be the cause.
- Return line blocked or frozenCommon
- Pressure sensor reads highPossible
- Dosing valve stuck closedPossible
Parts involved
- Reductant Pump
- Reductant Pressure Sensor
- Reductant Lines
P20E2 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.