P20DD
Exhaust Aftertreatment Fuel Pressure Sensor Circuit
A general electrical fault is reported on the aftertreatment fuel-pressure sensor — used to verify the dedicated HC-dosing rail is primed.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: hard
Symptoms
- Check engine light on
- Hard start, no start, or stalling under load
- Power loss especially at high load or rpm
- Possible long cranking time
Common causes
Ordered by how often each turns out to be the cause.
- Sensor failedCommon
- Harness faultPossible
Parts involved
- Aftertreatment Fuel Pressure Sensor
P20DD 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.