VOLVO
ECM-223B - Rear heated oxygen sensor (HO2S), bank 1. Signal missing
System
Engine Control Module (ECM)
Volvo models this fault code applies to
Applies to the following models:
9 modelsC30 (2007–2013), C70 (2006–2013), S40 (2004–2013), S60 (2001–2009), S80 (1999–2006), V50 (2004–2013), V70 (2000–2008), V70 XC / XC70 (2001–2007), XC90 (2003–)
Show models by year and engine (23)
- Volvo C30 (2007–2013)2007Engine B5254T3 only
- Volvo C30 (2007–2013)2008–2013Engine B5254T7 only
- Volvo C70 (2006–2013)2006–2007Engine B5254T3 only
- Volvo C70 (2006–2013)2008–2013Engine B5254T7 only
- Volvo S40 (2004–2013)2005–2007Engine B5254T3 only
- Volvo S40 (2004–2013)2008Engine B5254T3, B5254T7 only
- Volvo S40 (2004–2013)2009–2012Engine B5254T7 only
- Volvo S60 (2001–2009)2005–2006Engine B5204T5, B5244T4, B5244T5, B5254T2, B5254T4 only
- Volvo S60 (2001–2009)2007Engine B5204T5, B5244T5, B5254T2, B5254T4 only
- Volvo S60 (2001–2009)2008–2009Engine B5204T5, B5244T5, B5254T2 only
- Volvo S80 (1999–2006)2005–2006Engine B5204T5, B5244T4, B5254T2, B6294S2, B6294T only
- Volvo V50 (2004–2013)2005–2007Engine B5254T3 only
- Volvo V50 (2004–2013)2008–2012Engine B5254T7 only
- Volvo V70 (2000–2008)2005Engine B5204T5, B5244T4, B5244T5, B5254T2, B5254T4 only
- Volvo V70 (2000–2008)2006–2007Engine B5204T5, B5244T5, B5254T2, B5254T4 only
- Volvo V70 (2000–2008)2008Engine B5254T2 only
- Volvo V70 XC / XC70 (2001–2007)2005All engines except: D5244T
- Volvo V70 XC / XC70 (2001–2007)2006Engine B5244T4, B5254T2 only
- Volvo V70 XC / XC70 (2001–2007)2007Engine B5254T2 only
- Volvo XC90 (2003–)2005–2006Engine B5254T2, B6294T only
- Volvo XC90 (2003–)2007–2012Engine B5254T2 only
- Volvo XC90 (2003–)2013–2014Engine B5254T9 only
- Volvo XC90 (2003–)2015
What does this fault code mean?
The engine control module (ECM) controls the heating of the rear oxygen sensor on bank 1 by pulsing the current to the sensor heating element. The code is set when the signal from the sensor is too low while heating is switched off. With a diagnostic tool you can see whether the fault is permanent or intermittent. It is often caused by poor contact or by the power supply from the system relay being interrupted.
Possible causes
- Contact resistance and oxidation in the sensor terminals
- Open circuit in the power supply to the sensor from the system relay
- Damaged rear oxygen sensor
What you can do
- 1If you have a diagnostic tool: once the diagnostic is complete, read the fault status
- 2Fault found means the fault is permanent; No fault found means it is intermittent and not active now
- 3Check that the connector to the rear oxygen sensor is secure and not oxidised
- 4Use a multimeter to confirm the supply wire has continuity all the way from the system relay to the sensor
- 5Do not use rust solvent spray or grease in the sensor connector
- 6If the fault remains after these checks, have a workshop decide whether the sensor should be replaced
Symptoms you may notice1
- Malfunction indicator lamp (MIL) lit
What the fault can affect1
- Fuel trim is switched off
General guidance for car owners. Diagnosis on the car can point to a different cause.