VOLVO
ECM-0135 - Front heated oxygen sensor (HO2S), bank 1, heating. 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 lambda sensor has a heater that brings it up to temperature quickly after a cold start. The control module checks the voltage in the heater circuit and logs a fault when it does not match whether the heater is switched on or off. The fault appears during normal driving and lights the lamp. The cause may be an open wire, a wire shorted to ground, or a damaged sensor.
Possible causes
- Open circuit in the heater circuit signal wire
- Heater circuit signal wire shorted to ground
- Damaged front lambda sensor, bank 1
What you can do
- 1Read, clear the code and road test to see whether it returns
- 2Check that the connector at the lambda sensor is fully engaged and free from corrosion
- 3Follow the cable from the lambda sensor and look for chafing, pinched sections and loose clips
- 4With the sensor connector unplugged, use a multimeter to check that the heater circuit wire has no connection to ground (the body)
- 5If you have a diagnostic tool, check in live data whether the lambda sensor heater is on when the engine is cold and off when it is warm
- 6If the fault returns, have a workshop with diagnostic equipment check the wiring and the sensor
Symptoms you may notice1
- Malfunction indicator lamp (MIL) lit
General guidance for car owners. Diagnosis on the car can point to a different cause.