OBD-II reference

All 9.533 generic OBD-II codes, explained in detail.

Causes, inspection steps and sources — a comprehensive DIY archive. Created and maintained with love for the detail. Good luck and have fun!

Powertrain generic / SAE

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.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number– / DD

Possible causes

  • Sensor failed high
  • Harness fault medium

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

Inspection / repair

  • Difficulty: hard
  • DIY: shop recommended
  • Estimated cost: 150–1000 €
  • Estimated time: 0.7–3 h
  • Component: aftertreatment fuel pressure sensor
  • MIL / check engine light
  • emissions-relevant

Sources

References

How to read OBD-II codes

The first letter names the vehicle system, the second digit distinguishes generic from manufacturer-specific, the remaining digits group fault area and number.

PPowertrain: engine, transmission, emissions
BBody: chassis trim, comfort, interior
CChassis: suspension, brakes, steering
UNetwork: CAN, control modules, communication