VOLVO
ECM-0133 - Front heated oxygen sensor (HO2S), bank 1.Faulty signal
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:
3 modelsC30 (2007–2013), S40 (2004–2013), V50 (2004–2013)
Show models by year and engine (13)
- Volvo C30 (2007–2013)2007–2009Engine B4184S11, B4184S8, B4204S3 only
- Volvo C30 (2007–2013)2010Engine B4184S11, B4184S8, B4204S3, B4204S4 only
- Volvo C30 (2007–2013)2011–2013Engine B4204S3, B4204S4 only
- Volvo S40 (2004–2013)2005Engine B4184S11 only
- Volvo S40 (2004–2013)2006Engine B4184S11, B4184S8 only
- Volvo S40 (2004–2013)2007–2009Engine B4184S11, B4184S8, B4204S3 only
- Volvo S40 (2004–2013)2010Engine B4184S11, B4184S8, B4204S3, B4204S4 only
- Volvo S40 (2004–2013)2011–2012Engine B4204S3, B4204S4 only
- Volvo V50 (2004–2013)2005Engine B4184S11 only
- Volvo V50 (2004–2013)2006Engine B4184S11, B4184S8 only
- Volvo V50 (2004–2013)2007–2009Engine B4184S11, B4184S8, B4204S3 only
- Volvo V50 (2004–2013)2010Engine B4184S11, B4184S8, B4204S3, B4204S4 only
- Volvo V50 (2004–2013)2011–2012Engine B4204S3, B4204S4 only
What does this fault code mean?
The engine control module has detected that the front lambda sensor on bank 1 responds too slowly to changes in the fuel-air mixture. A healthy sensor follows these changes quickly, so when it lags, the control module cannot keep the mixture correct. Most often this is false air from leaks in the intake or exhaust system, though a damaged sensor can also cause it.
Possible causes
- Air leak at the intake manifold
- Air leak at the exhaust manifold
- Damaged front lambda sensor, bank 1
What you can do
- 1Read, note and clear the code, then road test to see whether it returns
- 2Check that the connector at the lambda sensor is fully engaged and free from corrosion
- 3With the engine running, listen for hissing near the intake manifold and its joints, and look for loose hoses or clips
- 4When the engine is warm, listen for exhaust leaks at the exhaust manifold and its joints. A leak before the sensor lets in false air that the sensor picks up
- 5With a diagnostic tool, check how the sensor value follows the accelerator. A slow response confirms the fault but not its cause
- 6If the leak check finds nothing, have a workshop with diagnostic equipment decide whether the lambda sensor needs replacing
Symptoms you may notice2
- Malfunction indicator lamp (MIL) lit
- Engine may start poorly or sometimes not at all
General guidance for car owners. Diagnosis on the car can point to a different cause.