Error code 15733 - NOx catalyst, bank 1 (Solution)

Error code.

Quote:

15733 - NOx catalyst, bank 1. P20EE 00 [101] - Efficiency too low

This issue occurs in various TDI engines when the engine control unit (ECU) determines that the efficiency of the SCR (Selective Catalytic Reduction) system is too low.

The following procedure is recommended:
- Ensure that the SCR tank is filled with a suitable AdBlue solution.
- Check if there is an update for the engine control unit software. See Software version check. - Inspect the NOx sensor and its wiring.
- The AGR system must function.
- Before replacing the NOx sensor (which is an expensive part), you can try cleaning it.

After replacing or cleaning the NOx sensor and clearing the error code in the engine control unit, the warning light on the instrument cluster continues to illuminate. You can either drive for a few kilometers and hope that everything now works correctly, or:

- Clear error codes from the engine control unit.
- Access VCDS and navigate to "01 - Engine Control Module (ECM)."
- Select the basic setting.
- Select "SCR Efficiency Test" from the drop-down menu.
- Click "Start".
- Press the brake and accelerator pedals (the display will prompt you to do so, the engine speed will increase to approximately 2000 rpm, and the glow plug indicator will illuminate in the instrument cluster).
- Let it sit for about 5 minutes.
- The process is complete when the engine speed drops. At the same time, a message is displayed in VCDS.
- Check if the message has disappeared from the AI.

See also topic:
https://community.dieselschrauber.org/en/viewtopic.php?t=30407