VOLVO
ECM-0131 - Front heated oxygen sensor (HO2S), bank 1.Signal too low
System
Engine Control Module (ECM)
Volvo models this fault code applies to
Applies to the following models:
3 modelsC30 (2007–2013), S40 (2004–2013), V50 (2004–2013)
Show models by year and engine (14)
- Volvo C30 (2007–2013)2007–2009Engine B4164S3, B4184S11, B4184S8, B4204S3 only
- Volvo C30 (2007–2013)2010Engine B4164S3, B4184S11, B4184S8, B4204S3, B4204S4 only
- Volvo C30 (2007–2013)2011–2012Engine B4164S3, B4204S3, B4204S4 only
- Volvo C30 (2007–2013)2013Engine B4204S3, B4204S4 only
- Volvo S40 (2004–2013)2005Engine B4164S3, B4184S11 only
- Volvo S40 (2004–2013)2006Engine B4164S3, B4184S11, B4184S8 only
- Volvo S40 (2004–2013)2007–2009Engine B4164S3, B4184S11, B4184S8, B4204S3 only
- Volvo S40 (2004–2013)2010Engine B4164S3, B4184S11, B4184S8, B4204S3, B4204S4 only
- Volvo S40 (2004–2013)2011–2012Engine B4164S3, B4204S3, B4204S4 only
- Volvo V50 (2004–2013)2005Engine B4164S3, B4184S11 only
- Volvo V50 (2004–2013)2006Engine B4164S3, B4184S11, B4184S8 only
- Volvo V50 (2004–2013)2007–2009Engine B4164S3, B4184S11, B4184S8, B4204S3 only
- Volvo V50 (2004–2013)2010Engine B4164S3, B4184S11, B4184S8, B4204S3, B4204S4 only
- Volvo V50 (2004–2013)2011–2012Engine B4164S3, B4204S3, B4204S4 only
What does this fault code mean?
The front oxygen sensor reports a lean mixture where a rich one is expected, or a value below the set limit. The cause is most often a break or a short to ground in the signal wire, but a damaged sensor can also cause the fault.
Possible causes
- Break in the signal wire
- Signal wire shorted to ground
- Damaged front oxygen sensor
What you can do
- 1With the ignition off, unplug the front oxygen sensor connector and check the contacts for looseness, contact resistance and oxidation
- 2Use a multimeter to check that the signal wire does not break and has no short to ground, moving the wiring as you measure
- 3If the wires are sound and the fault remains, have a workshop replace the front oxygen sensor
Symptoms you may notice1
- Malfunction indicator lamp (MIL) lights up
General guidance for car owners. Diagnosis on the car can point to a different cause.