VOLVO
ECM-120A - Intake air temperature (IAT) sensor inlet. Faulty signal
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:
7 modelsC70 Cabriolet (1998–2005), C70 Coupé (1998–2002), S60 (2001–2009), S70 (1997–2000), S80 (1999–2006), V70 (1997–2000), V70 (2000–2008)
Show models by year and engine (19)
- Volvo C70 Cabriolet (1998–2005)2000Engine B5244S only
- Volvo C70 Coupé (1998–2002)1999Engine B5254S DENSO only
- Volvo C70 Coupé (1998–2002)2000Engine B5244S only
- Volvo S60 (2001–2009)2001, 2009Engine B5244S, B5244S2 only
- Volvo S60 (2001–2009)2002Engine B5244S, B5244S2, B5244SG, B5244SG2 only
- Volvo S60 (2001–2009)2003–2005Engine B5244S, B5244S2, B5244S6, B5244SG, B5244SG2 only
- Volvo S60 (2001–2009)2006Engine B5244S, B5244S2, B5244S6, B5244SG only
- Volvo S60 (2001–2009)2007–2008Engine B5244S, B5244S2, B5244SG only
- Volvo S70 (1997–2000)1999Engine B5254S DENSO only
- Volvo S70 (1997–2000)2000Engine B5244S, B5244S2, B5244SG, B5244SG2 only
- Volvo S80 (1999–2006)1999–2000Engine B5244S, B5244S2 only
- Volvo S80 (1999–2006)2001, 2006Engine B5244S, B5244S2, B5244SG only
- Volvo S80 (1999–2006)2002–2005Engine B5244S, B5244S2, B5244SG, B5244SG2 only
- Volvo V70 (1997–2000)1999Engine B5254S DENSO only
- Volvo V70 (1997–2000)2000Engine B5244S, B5244S2, B5244SG, B5244SG2 only
- Volvo V70 (2000–2008)2001, 2007–2008Engine B5244S, B5244S2, B5244SG only
- Volvo V70 (2000–2008)2002Engine B5244S, B5244S2, B5244SG, B5244SG2 only
- Volvo V70 (2000–2008)2003–2005Engine B5244S, B5244S2, B5244S6, B5244SG, B5244SG2 only
- Volvo V70 (2000–2008)2006Engine B5244S, B5244S2, B5244S6, B5244SG only
What does this fault code mean?
The engine control module compares the intake air temperature sensor with the engine and outside temperature sensors after the car has been switched off for a long time. If the air temperature deviates too much from the other sensors' values, the code is set. The code is checked with the ignition on, once the engine has cooled down properly.
Possible causes
- Faulty signal from the intake air temperature sensor, which sits in the mass air flow sensor
- Contact resistance in the connector
- Damaged intake air temperature sensor inside the mass air flow sensor
What you can do
- 1With your own diagnostic tool, compare the air temperature in live data with the engine temperature after a night without driving; the values should be close
- 2Check that the mass air flow sensor connector is secure and free from oxidation
- 3Clear the code and road test to see whether it returns
- 4If the temperature is now correct, the fault was probably caused by poor contact in the connector
- 5If the fault remains, have a workshop replace the mass air flow sensor, since the air temperature sensor is part of it and cannot be replaced separately
Symptoms you may notice1
- The malfunction indicator lamp comes on
General guidance for car owners. Diagnosis on the car can point to a different cause.