VOLVO
ECM-2840 - Heated oxygen sensor (HO2S). Signal outside its permitted range
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:
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 information about the fuel and air mixture. The code is stored when the control module finds the sensor signal implausibly high, which can be caused by a short circuit in the signal cable or a damaged sensor.
Possible causes
- Short circuit in the signal cable
- Damaged heated oxygen sensor
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 that the oxygen sensor connections are secure and free from play, oxidation and contact resistance
- 3With the car switched off, use a multimeter to check that the signal cable is not shorted to ground or to supply voltage
- 4If you have a diagnostic tool: check in live data whether the oxygen sensor value is implausibly high while driving
Symptoms you may notice1
- Message in the information display
General guidance for car owners. Diagnosis on the car can point to a different cause.