VOLVO
ECM-2339 - Cylinder #4 Above Knock Threshold
System
Engine Control Module (ECM)
Volvo models this fault code applies to
Applies to the following models:
3 modelsC30 (2007–2013), S40 (2004–2013), V50 (2004–2013)
Show models by year and engine (9)
- Volvo C30 (2007–2013)2008–2009Engine B4184S11, B4184S8, B4204S3 only
- Volvo C30 (2007–2013)2010Engine B4184S11, B4184S8, B4204S3, B4204S4 only
- Volvo C30 (2007–2013)2011–2013Engine B4204S3, B4204S4 only
- Volvo S40 (2004–2013)2008–2009Engine B4184S11, B4184S8, B4204S3 only
- Volvo S40 (2004–2013)2010Engine B4184S11, B4184S8, B4204S3, B4204S4 only
- Volvo S40 (2004–2013)2011–2012Engine B4204S3, B4204S4 only
- Volvo V50 (2004–2013)2008–2009Engine B4184S11, B4184S8, B4204S3 only
- Volvo V50 (2004–2013)2010Engine B4184S11, B4184S8, B4204S3, B4204S4 only
- Volvo V50 (2004–2013)2011–2012Engine B4204S3, B4204S4 only
What does this fault code mean?
Cylinder 4 has produced too many combustion knock events, and the engine control module (ECM) responds by adjusting the ignition. The code is set only once the knock count for cylinder 4 exceeds the module's level. The knock sensor on the engine block supplies the data the module uses.
Possible causes
- Engine running on a lean fuel/air mixture
- Poor fuel quality, for example summer fuel in winter
- Engine running too hot
- Intake air temperature too high
- Knock sensor fitted loosely
- Damaged knock sensor
What you can do
- 1Read and clear the code, then road test to see whether it returns
- 2Fill up with petrol of the right grade for the season, and avoid fuel that causes knock
- 3Make sure the knock sensor connector is secure and has not taken in moisture
- 4If you have a diagnostic tool: compare the ignition timing adjustment for cylinder 4 with the other cylinders in live data during driving
- 5If the fault remains, have a workshop decide whether the knock sensor needs replacing
Symptoms you may notice1
- Poor performance
General guidance for car owners. Diagnosis on the car can point to a different cause.