VOLVO
ECM-28B0 - Heated oxygen sensor (HO2S). Faulty signal
System
Engine Control Module (ECM)
Volvo models this fault code applies to
Applies to the following models:
8 modelsC30 (2007–2013), C70 (2006–2013), S40 (2004–2013), S60 (2001–2009), V50 (2004–2013), V70 (2000–2008), V70 XC / XC70 (2001–2007), XC90 (2003–)
Show models by year and engine (20)
- Volvo C30 (2007–2013)2007Engine D5244T8, D5244T9 only
- Volvo C30 (2007–2013)2008–2010Engine D5244T13, D5244T8, D5244T9 only
- Volvo C70 (2006–2013)2007Engine D5244T8, D5244T9 only
- Volvo C70 (2006–2013)2008–2010Engine D5244T13, D5244T8, D5244T9 only
- Volvo S40 (2004–2013)2006Engine D5244T8 only
- Volvo S40 (2004–2013)2007Engine D5244T8, D5244T9 only
- Volvo S40 (2004–2013)2008–2010Engine D5244T13, D5244T8, D5244T9 only
- Volvo S60 (2001–2009)2006Engine D5244T4, D5244T5, D5244T6, D5244T7 only
- Volvo S60 (2001–2009)2007–2009Engine D5244T4, D5244T5, D5244T7 only
- Volvo V50 (2004–2013)2006Engine D5244T8 only
- Volvo V50 (2004–2013)2007Engine D5244T8, D5244T9 only
- Volvo V50 (2004–2013)2008–2010Engine D5244T13, D5244T8, D5244T9 only
- Volvo V70 (2000–2008)2006Engine D5244T4, D5244T5, D5244T6, D5244T7 only
- Volvo V70 (2000–2008)2007Engine D5244T4, D5244T5, D5244T7 only
- Volvo V70 (2000–2008)2008Engine D5244T5, D5244T7 only
- Volvo V70 XC / XC70 (2001–2007)2006–2007Engine D5244T4 only
- Volvo XC90 (2003–)2006–2007Engine D5244T4 only
- Volvo XC90 (2003–)2008–2010Engine D5244T4, D5244T5 only
- Volvo XC90 (2003–)2011Engine D5244T18, D5244T4, D5244T5 only
- Volvo XC90 (2003–)2012All engines except: B5254T2, B6324S5
What does this fault code mean?
The engine control module follows the oxygen sensor signal on the fuel and air mixture. When the signal moves outside what the control module expects during the current drive, the code is set. The cause may be a break in the signal wire, a damaged sensor or a fault inside the engine control module itself.
Possible causes
- Break in the signal wire
- Damaged oxygen sensor
- Fault inside the engine control module (ECM) itself
What you can do
- 1Read the code, clear it and drive for a while to see whether it returns
- 2Switch off the ignition and check the oxygen sensor connector: it should be secure, clean and free from oxidation
- 3With the car switched off, use a multimeter to check that the signal wire is not broken
- 4If the signal wire is intact but the fault remains, have a workshop check the sensor and the control module with diagnostic equipment
Symptoms you may notice1
- Message in the information display
General guidance for car owners. Diagnosis on the car can point to a different cause.