VOLVO
ECM-122D - Mass air flow (MAF) sensor. Flow too low
System
Engine Control Module (ECM)
Volvo models this fault code applies to
Applies to the following models:
4 modelsC30 (2007–2013), C70 (2006–2013), S40 (2004–2013), V50 (2004–2013)
Show models by year and engine (9)
- Volvo C30 (2007–2013)2007Engine B5254T3 only
- Volvo C30 (2007–2013)2008–2013Engine B5254T7 only
- Volvo C70 (2006–2013)2006–2007Engine B5254T3 only
- Volvo C70 (2006–2013)2008–2013Engine B5254T7 only
- Volvo S40 (2004–2013)2005–2007Engine B5254T3 only
- Volvo S40 (2004–2013)2008Engine B5254T3, B5254T7 only
- Volvo S40 (2004–2013)2009–2012Engine B5254T7 only
- Volvo V50 (2004–2013)2005–2007Engine B5254T3 only
- Volvo V50 (2004–2013)2008–2012Engine B5254T7 only
What does this fault code mean?
The mass air flow sensor is measuring less air than the engine control module has calculated, and the code is set. The cause may be a leak in the intake, poor contact in the sensor connector, a cable fault or a damaged sensor.
Possible causes
- Air leakage in the intake system
- Contact resistance in the mass air flow connectors
- Signal wire short-circuited to ground
- Open circuit in the signal wire
- Open circuit in the power supply
- Damaged mass air flow sensor
What you can do
- 1Check the mass air flow sensor connector for contact resistance and oxidation
- 2Check the intake for leaks, since a leak makes the measured air quantity too low
- 3With your own diagnostic tool, read the air flow at idle; it varies with engine temperature and load and is normally higher when the engine is cold
- 4If the fault remains, have a workshop check the mass air flow sensor
Symptoms you may notice2
- The malfunction indicator lamp comes on
- The engine performs worse
What the fault can affect3
- Boost pressure is calculated instead of measured
- Rear oxygen sensor control is switched off
- Misfire detection is switched off
General guidance for car owners. Diagnosis on the car can point to a different cause.