VOLVO
ECM-301A - Camshaft position (CMP) sensor, exhaust. Faulty signal
System
Engine Control Module (ECM)
Volvo models this fault code applies to
Applies to the following models:
7 modelsC30 (2007–2013), C70 (2006–2013), S40 (2004–2013), S60 (2001–2009), S80 (1999–2006), V50 (2004–2013), V70 (2000–2008)
Show models by year and engine (13)
- Volvo C30 (2007–2013)2007–2011Engine B5244S4 only
- Volvo C70 (2006–2013)2006All engines except: B5254T3
- Volvo C70 (2006–2013)2007–2010Engine B5244S4, B5244S5 only
- Volvo C70 (2006–2013)2011Engine B5244S4 only
- Volvo S40 (2004–2013)2004Engine B5244S4, B5244S5 only
- Volvo S40 (2004–2013)2005–2010Engine B5244S4, B5244S5, B5244S7 only
- Volvo S60 (2001–2009)2003–2006Engine B5244S, B5244S6 only
- Volvo S60 (2001–2009)2007–2009Engine B5244S only
- Volvo S80 (1999–2006)2003–2006Engine B5244S only
- Volvo V50 (2004–2013)2004Engine B5244S4, B5244S5 only
- Volvo V50 (2004–2013)2005–2010Engine B5244S4, B5244S5, B5244S7 only
- Volvo V70 (2000–2008)2003–2006Engine B5244S, B5244S6 only
- Volvo V70 (2000–2008)2007–2008Engine B5244S only
What does this fault code mean?
The control module checks the signal from the exhaust camshaft position sensor and counts the camshaft flanks during the crankshaft revolutions. If fewer flanks than expected are found, the code is stored. The fault is checked once the engine speed has risen above a set level. The cause may be a connection fault, incorrectly adjusted camshafts, or a sensor that is incorrectly fitted or damaged.
Possible causes
- Contact resistance in the connections
- Incorrectly adjusted camshafts
- Signal wire short-circuited to supply voltage
- Temporary open circuit in the wiring or a splice
- Incorrectly installed camshaft position sensor
- Damaged exhaust camshaft position sensor
What you can do
- 1If another fault code for camshaft position is stored, investigate that one first
- 2Check the camshaft position sensor connector for contact resistance and oxidation
- 3Check that the camshaft position sensor is firmly fitted in the correct position and that the rotor on the camshaft is not damaged
- 4Read the fault status with the engine running: Fault found means the fault is still present, No fault detected means it was intermittent
- 5If other checks show nothing: have a workshop check the camshaft adjustment
Symptoms you may notice2
- The engine is difficult to start
- The engine misfires
What the fault can affect1
- The control module uses the engine speed sensor signal if it is working
General guidance for car owners. Diagnosis on the car can point to a different cause.