VOLVO
ECM-28D0 - Heated oxygen sensor (HO2S). Signal too low
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 oxygen sensor gives the engine control module its reading of the fuel and air mixture. This code is set when the signal for oxygen content is judged incorrect, here too low. It is detected during engine braking, and the cause may be a short to ground in the signal wire, a damaged sensor or a fault in the control module.
Possible causes
- Signal cable shorted to ground
- Damaged heated oxygen sensor
- Fault inside the control module
What you can do
- 1Read the code, clear it and drive with engine braking to see whether it returns
- 2Switch off the ignition and check the oxygen sensor connections: they should be secure, clean and free from oxidation and play
- 3With the car switched off, use a multimeter to check that the signal cable has no contact with ground
- 4If you have a diagnostic tool: see whether the oxygen sensor value in live data changes when the engine brakes
- 5If the wiring is in order 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.