Hours: 07–23 daily

TuningBot DTC Database · v4.37.15

P20F3 SCR NOx Pre - Catalyst Efficiency Below Threshold Bank 2

Generic (OBD-II) interpretation in the TuningBot DTC database.

P · PowertrainEmissionsOBD2

What P20F3 means

P20F3
SCR NOx Pre - Catalyst Efficiency Below Threshold Bank 2 Generic · emissions Data confidence 85%

The control module calculated that SCR NOx Pre - Catalyst efficiency dropped below the calibrated threshold for this application.

Symptoms

  • MIL or SCR/AdBlue warning illuminated
  • Possible start-count-down or torque limitation on some applications

Possible causes

  • Reductant quality or level fault
  • Dosing valve or supply module fault
  • NOx sensor fault
  • Frozen or crystallized reductant lines
  • Wiring or connector fault

Recommended checks

  • Read NOx sensor values and dosing system status
  • Check reductant level and quality data
  • Inspect dosing valve, lines and heater operation
  • Check wiring and connectors of the SCR components
  • Check for OEM technical bulletins and software updates

Related and nearby codes

How to read P20F3

P

Powertrain: engine, transmission and driveline systems.

2

Generic SAE-standard code: same meaning on every make.

0F3

Specific fault index within the subsystem.

Frequently asked questions about P20F3

What does P20F3 mean?

SCR NOx Pre - Catalyst Efficiency Below Threshold Bank 2. The control module calculated that SCR NOx Pre - Catalyst efficiency dropped below the calibrated threshold for this application.

Is P20F3 generic or manufacturer-specific?

P20F3 is a generic OBD-II code: it has the same meaning on every make and model that follows the SAE standard.

Can TuningBot remove P20F3 at file level?

If the fault logic lives in the ECU calibration, yes: our DTC Removal file service disables the specific fault entry. Checksum correction is not included: it is a separate, optional service. Not sure whether your case qualifies? Request a free assessment and our engineers will check your ECU file.

Other file services

ECU tuningDyno-tested results by model and engine See the results →

← Search the full DTC database