VOLVO
ECM-280A - Front heated oxygen sensor (HO2S), bank 1. Signal missing. Intermittent fault
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:
6 modelsC70 Cabriolet (1998–2005), S60 (2001–2009), S80 (1999–2006), V70 (2000–2008), V70 XC / XC70 (2001–2007), XC90 (2003–)
Show models by year and engine (17)
- Volvo C70 Cabriolet (1998–2005)2003–2005
- Volvo S60 (2001–2009)2001All engines except: B5244S, B5244S2, D5244T
- Volvo S60 (2001–2009)2002Engine B5204T5, B5234T3, B5234T7, B5244T3 only
- Volvo S60 (2001–2009)2003Engine B5204T5, B5234T3, B5234T7, B5244T3, B5254T2 only
- Volvo S60 (2001–2009)2004Engine B5204T5, B5234T3, B5234T7, B5254T2, B5254T4 only
- Volvo S80 (1999–2006)1999–2000All engines except: B5244S, B5244S2, D5252T MSA 15.8
- Volvo S80 (1999–2006)2001Engine B5204T5, B5234T7, B5244T3, B6284T, B6294S only
- Volvo S80 (1999–2006)2002Engine B5204T5, B5234T7, B5244T3, B6294S2, B6294T only
- Volvo S80 (1999–2006)2003Engine B5204T5, B5234T7, B5244T3, B5254T2, B6294S2, B6294T only
- Volvo S80 (1999–2006)2004Engine B5204T5, B5234T7, B5254T2, B6294S2, B6294T only
- Volvo V70 (2000–2008)2000All engines except: D5252T MSA 15.8
- Volvo V70 (2000–2008)2001–2002Engine B5204T5, B5234T3, B5234T7, B5244T3 only
- Volvo V70 (2000–2008)2003Engine B5204T5, B5234T3, B5234T7, B5244T3, B5254T2 only
- Volvo V70 (2000–2008)2004Engine B5204T5, B5234T3, B5234T7, B5254T2, B5254T4 only
- Volvo V70 XC / XC70 (2001–2007)2001–2002
- Volvo V70 XC / XC70 (2001–2007)2003–2004All engines except: D5244T
- Volvo XC90 (2003–)2003–2004All engines except: D5244T
What does this fault code mean?
The engine control module has detected that the signal from the front heated oxygen sensor on bank 1 is missing. The fault is intermittent: it has occurred at some point but may not be present now. It may be caused by a short circuit between the sensor's signal wires, or between one of the heater wires and the sensor's other wiring.
Possible causes
- Short circuit between the signal cables (+) and (-)
- Short circuit between one of the heater cables and the sensor's other wiring
What you can do
- 1Read the code, note it, clear it and drive the car for a while to see whether it returns
- 2Inspect the wiring to the front oxygen sensor for chafing, pinched areas and places where wires touch each other
- 3Check the connector at the oxygen sensor so it is secure and clean. Do not spray rust solvent or grease into the connector
- 4With the car switched off, use a multimeter to check that the signal wires have no contact with each other or with the heater wires
- 5If you have a diagnostic tool: check in live data whether the oxygen sensor value changes while driving. A value that stays completely still indicates that the signal is missing
- 6If the fault returns, have a workshop check the wiring and the sensor with diagnostic equipment
Symptoms you may notice1
- Malfunction indicator lamp (MIL) lit
What the fault can affect2
- Control with the rear oxygen sensor is switched off
- Catalytic converter diagnostic is switched off
General guidance for car owners. Diagnosis on the car can point to a different cause.