VOLVO
ECM-2910 - Front heated oxygen sensor (HO2S) preheating, bank 2. Signal missing
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:
2 modelsS80 (1999–2006), XC90 (2003–)
Show models by year and engine (2)
What does this fault code mean?
Although the code is named signal missing, it is set when the heating of the front oxygen sensor on bank 2 does not work within a set time after the exhaust system has reached dew point. The sensor needs heating to give a usable signal, so the fault affects the regulation.
Possible causes
- Break in the supply feed from the relay that powers the heater
- Contact resistance and oxidation in the connections
- Defective oxygen sensor
What you can do
- 1Check that the connector at the bank 2 oxygen sensor is clean and secure, free from contact resistance and oxidation
- 2If you have a diagnostic tool: start the engine, let it idle and read the status for the front oxygen sensor. Wait if the diagnosis is still running
- 3With the ignition on, use a multimeter to check that the supply from the system relay reaches the sensor
- 4If the connector and supply are in order but the fault remains, have a workshop check the sensor and replace it if needed
Symptoms you may notice1
- Malfunction indicator lamp (MIL) lights
What the fault can affect1
- Fuel trim control is switched off
General guidance for car owners. Diagnosis on the car can point to a different cause.