VOLVO
ECM-34F0 - Knock sensor (KS), test pulse. Signal too high/Signal too low. Intermittent fault
System
Engine Control Module (ECM)
Volvo models this fault code applies to
This fault code has different meanings depending on model, model year or engine. Select the meaning that applies to your car.
Applies to the following models:
6 modelsC70 Cabriolet (1998–2005), S60 (2001–2009), S80 (1999–2006), V70 (2000–2008), V70 XC / XC70 (2001–2007), XC90 (2003–)
Show models by year and engine (17)
- Volvo C70 Cabriolet (1998–2005)2003–2005
- Volvo S60 (2001–2009)2001All engines except: B5244S, B5244S2, D5244T
- Volvo S60 (2001–2009)2002Engine B5204T5, B5234T3, B5234T7, B5244T3 only
- Volvo S60 (2001–2009)2003Engine B5204T5, B5234T3, B5234T7, B5244T3, B5254T2 only
- Volvo S60 (2001–2009)2004Engine B5204T5, B5234T3, B5234T7, B5254T2, B5254T4 only
- Volvo S80 (1999–2006)1999–2000All engines except: B5244S, B5244S2, D5252T MSA 15.8
- Volvo S80 (1999–2006)2001Engine B5204T5, B5234T7, B5244T3, B6284T, B6294S only
- Volvo S80 (1999–2006)2002Engine B5204T5, B5234T7, B5244T3, B6294S2, B6294T only
- Volvo S80 (1999–2006)2003Engine B5204T5, B5234T7, B5244T3, B5254T2, B6294S2, B6294T only
- Volvo S80 (1999–2006)2004Engine B5204T5, B5234T7, B5254T2, B6294S2, B6294T only
- Volvo V70 (2000–2008)2000All engines except: D5252T MSA 15.8
- Volvo V70 (2000–2008)2001–2002Engine B5204T5, B5234T3, B5234T7, B5244T3 only
- Volvo V70 (2000–2008)2003Engine B5204T5, B5234T3, B5234T7, B5244T3, B5254T2 only
- Volvo V70 (2000–2008)2004Engine B5204T5, B5234T3, B5234T7, B5254T2, B5254T4 only
- Volvo V70 XC / XC70 (2001–2007)2001–2002
- Volvo V70 XC / XC70 (2001–2007)2003–2004All engines except: D5244T
- Volvo XC90 (2003–)2003–2004All engines except: D5244T
What does this fault code mean?
The control module's own knock control circuit has detected a fault during the test pulse. The fault is stored as intermittent, so it may have been present before without being active now. It can show up as a signal that is too high or too low.
Possible causes
- Defective engine control module
What you can do
- 1Clear the code and road test the car to see whether it comes back
- 2If you have a diagnostic tool: read the fault status, where "No fault found" means the fault is not active right now
- 3Check that the engine control module connectors are secure and not corroded
- 4If the fault remains, have a workshop check and, if needed, replace the engine control module with diagnostic equipment
Symptoms you may notice1
- Malfunction indicator (emissions lamp) is lit
What the fault can affect2
- Safety retardation of ignition timing
- Boost pressure is lowered
General guidance for car owners. Diagnosis on the car can point to a different cause.