VOLVO
ECM-0320 - Engine speed (RPM) sensor signal. Signal missing
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 (13)
- Volvo C30 (2007–2013)2007–2009Engine 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)2005Engine B4184S11 only
- Volvo S40 (2004–2013)2006Engine B4184S11, B4184S8 only
- Volvo S40 (2004–2013)2007–2009Engine 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)2005Engine B4184S11 only
- Volvo V50 (2004–2013)2006Engine B4184S11, B4184S8 only
- Volvo V50 (2004–2013)2007–2009Engine 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?
The engine control module (ECM) receives no signal from the impulse sensor, which tells it how fast the engine is turning and where the crankshaft is. Without that signal the control module does not know when to fire the ignition and inject fuel. The code is set both at start and while driving, and the causes are poor contact or a damaged impulse sensor.
Possible causes
- Contact resistance or oxidation in the connections to the impulse sensor
- Damaged impulse sensor
What you can do
- 1Read out the fault code, erase it and check whether it returns at the next start
- 2Switch off the ignition and unplug the impulse sensor connector. Check the connector for looseness, contact resistance and oxidation
- 3Look for chafing, pinched areas and breaks in the wiring from the impulse sensor, especially where it runs close to the engine
- 4Use a multimeter to check that the signal wires from the impulse sensor have no open circuit and no short to ground or voltage
- 5With a diagnostic tool, read the crank speed signal in live data while cranking. If it is missing, the signal is not arriving
- 6If the fault remains, have a workshop with diagnostic equipment check and, if needed, replace the impulse sensor
Symptoms you may notice2
- The malfunction indicator lamp (MIL) is lit
- The starter motor cranks but the engine does not start
General guidance for car owners. Diagnosis on the car can point to a different cause.