VOLVO
ECM-2920 - Heated oxygen sensor (HO2S) preheating, bank 2. Faulty signal. Intermittent fault
System
Engine Control Module (ECM)
Volvo models this fault code applies to
Applies to the following models:
1 modelS80 (1999–2006)
Show models by year and engine (1)
What does this fault code mean?
The resistance in the heating circuit of the front oxygen sensor on bank 2 has been out of range, either too high or too low, for a set time, so the code is set. The fault is intermittent, meaning it has occurred at some point but may not be present now. Possible causes are poor contact, an interruption in the supply from the system relay or a defective sensor.
Possible causes
- Contact resistance and oxidation in the connections
- Interruption in the supply from the system relay
- Defective oxygen sensor
- Break in the signal cable
What you can do
- 1Read the code, clear it and drive for a while to see whether it returns
- 2Check the bank 2 sensor connector for oxidation and contact resistance, and make sure it is secure
- 3With the car switched off, use a multimeter to check that the signal wire is not broken
- 4With the ignition on, check that the supply from the system relay reaches the sensor
- 5If you have a diagnostic tool: after the engine has run a while, read the front sensor fault status. If the fault is no longer active, it was probably intermittent
Symptoms you may notice1
- Malfunction indicator lamp (MIL) lights
General guidance for car owners. Diagnosis on the car can point to a different cause.