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

P2337

Cylinder 2 Above Knock Threshold

The knock sensor channel for cylinder 2 has registered combustion noise above the calibrated knock threshold beyond what the spark retard map can correct. Often associated with low-octane fuel, EGR malfunction or carbon-induced hot spots.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number3 / 37

Possible causes

  • Low octane fuel used high
  • Carbon deposits causing pre-ignition medium

Inspection / repair

  • Difficulty: medium
  • DIY: possible
  • Estimated cost: 40–800 €
  • Estimated time: 0.5–4 h
  • Component: knock sensor
  • Component: spark plug
  • 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