VOLVO
ECM-123D - Air mass. Signal 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 measured air quantity falls below the expected value by too wide a margin, and the lambda adaptation is also outside its normal range. The code is set, and the cause may be a leak, a blockage or a damaged air mass sensor.
Possible causes
- Poor contact or oxidation at the air mass sensor connector
- Leakage in the intake
- Dirty or blocked intake system
- Damaged mass air flow sensor
What you can do
- 1Check that the air mass sensor connector is clean and firmly seated
- 2Check the intake hoses for leaks and cracks
- 3Check that the throttle is not dirty, and clean it if needed
- 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 rather than measured
- Rear oxygen sensor control is not carried out
- Misfire detection is switched off
General guidance for car owners. Diagnosis on the car can point to a different cause.