VOLVO
ECM-220F - Rear heated oxygen sensor (HO2S). Faulty signal
System
Engine Control Module (ECM)
Volvo models this fault code applies to
Applies to the following models:
9 modelsC70 Cabriolet (1998–2005), C70 Coupé (1998–2002), S40 (2004–2013), S60 (2001–2009), S70 (1997–2000), S80 (1999–2006), V50 (2004–2013), V70 (1997–2000), V70 (2000–2008)
Show models by year and engine (24)
- 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 S40 (2004–2013)2004Engine B5244S4, B5244S5 only
- Volvo S60 (2001–2009)2001Engine B5244S, B5244S2 only
- Volvo S60 (2001–2009)2002Engine B5244S, B5244S2, B5244SG, B5244SG2 only
- Volvo S60 (2001–2009)2003–2004Engine B5244S, B5244S2, B5244S6, B5244SG, B5244SG2 only
- Volvo S60 (2001–2009)2005Engine B5244SG, B5244SG2 only
- Volvo S60 (2001–2009)2006–2008Engine 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)2001Engine B5244S, B5244S2, B5244SG only
- Volvo S80 (1999–2006)2002–2004Engine B5244S, B5244S2, B5244SG, B5244SG2 only
- Volvo S80 (1999–2006)2005Engine B5244SG, B5244SG2 only
- Volvo S80 (1999–2006)2006Engine B5244SG only
- Volvo V50 (2004–2013)2004Engine B5244S4, B5244S5 only
- Volvo V70 (1997–2000)1999Engine B5254S DENSO only
- Volvo V70 (1997–2000)2000Engine B5244S, B5244S2, B5244SG, B5244SG2 only
- Volvo V70 (2000–2008)2001Engine B5244S, B5244S2, B5244SG only
- Volvo V70 (2000–2008)2002Engine B5244S, B5244S2, B5244SG, B5244SG2 only
- Volvo V70 (2000–2008)2003–2004Engine B5244S, B5244S2, B5244S6, B5244SG, B5244SG2 only
- Volvo V70 (2000–2008)2005Engine B5244SG, B5244SG2 only
- Volvo V70 (2000–2008)2006–2008Engine B5244SG only
What does this fault code mean?
The engine control module continuously checks nine adaptation areas for the lambda regulation, and their values are added together. When the total becomes too large, that is when the mixture lies outside the permitted limits, the code is set. The cause can be a defective rear oxygen sensor, an air leak in the intake or exhaust, or a damaged rear sensor.
Possible causes
- Defective rear oxygen sensor
- Intake air leakage
- Air leakage in the exhaust system
- Damaged rear oxygen sensor
What you can do
- 1Have a diagnostic tool? Read the code status with the engine running; if it still shows as active the fault is permanent, otherwise it has been intermittent
- 2Check the exhaust system for air leaks at joints and seams
- 3Check that the hoses and connections on the intake side are secure, since an air leak gives the same code
- 4Do not use rust solvent spray or grease in the oxygen sensor connector, and check that the connector is clean
- 5If the exhaust is sealed and the connector is clean but the fault remains, have a workshop try a new rear oxygen sensor
Symptoms you may notice1
- The malfunction indicator lamp (MIL) comes on
What the fault can affect1
- Control using the rear oxygen sensor is switched off
General guidance for car owners. Diagnosis on the car can point to a different cause.