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

P2211

NOx Sensor Heater Sense Circuit Intermittent (Bank 2)

The heater sense line on the bank 2 NOx sensor produces intermittent readings. Often a thermal fault inside the sensor or a connector under temperature cycling.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number2 / 11

Possible causes

  • Connector intermittent under temperature high
  • Sensor heater intermittent when hot medium
  • Harness routed against vibrating component low

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)

Inspection / repair

  • Difficulty: medium
  • DIY: possible
  • Estimated cost: 300–1000 €
  • Estimated time: 0.5–2 h
  • Component: nox sensor b2
  • Component: nox sensor heater
  • MIL / check engine light
  • emissions-relevant
  • drive cycle required

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