Powertrain, generic (extended)

P2346 Cylinder 11 Above Knock/Combustion Vibration Sensor Threshold

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

Cylinders 11 and 12 exist only on V12 engines, for example BMW's V12 in the 7 and 8 Series, Mercedes-Benz's M120 and its successors, and the V12s of Ferrari, Lamborghini and Aston Martin. P2346 reports that cylinder 11 has knocked above the threshold that the knock control allows in its crank-angle window. With twelve combustions per two crank turns the windows are short, so the module depends on clean crank and sensor signals to assign knock correctly; a fault on the bank sensor or noise from nearby parts can shift the blame. No manufacturer was found that publishes P2346; GM and Saab file a lone knocking cylinder under P0324. Retarded spark on one cylinder costs some power, but continuing knock can destroy the piston.

Likely causes

Deposits or hot spots in cylinder 11
Fuel below the required octane rating
Disturbed crank or knock sensor signal shifting the cylinder assignment

Symptoms

  • MIL on
  • Slight loss of power
  • Possibly audible pinging

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€0–4,000
Time0.5–8 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

knock sensorknock sensor wiringcylinder 11 combustion

Related codes

P2345P2347P0324P0325P0311

References: en.wikipedia.org, saabwisonline.com, en.wikipedia.org, law.cornell.edu.