VOLVO
ECM-P005321 - HO2S Heater Resistance (Bank 1, Sensor 1). General Signal Failures. Signal too low
System
Engine Control Module (ECM)
Volvo models this fault code applies to
Applies to the following models:
5 modelsS80 (2007–), V70 (2008–), XC60 (2009–), XC70 (2008–), XC90 (2003–)
Show models by year and engine (6)
- Volvo S80 (2007–)2007–2009Engine D5244T4, D5244T5 only
- Volvo V70 (2008–)2008–2009Engine D5244T4, D5244T5 only
- Volvo XC60 (2009–)2009All engines except: B6304T2
- Volvo XC70 (2008–)2008All engines except: B6324S
- Volvo XC70 (2008–)2009Engine D5244T4, D5244T5 only
- Volvo XC90 (2003–)2013–2014Engine D5244T18, D5244T5 only
What does this fault code mean?
The oxygen sensor gives the engine control module information about the fuel and air mixture. The code is set when the module detects that the sensor's calibration signal is wrong, here too low. The fault can only be checked when the sensor is calibrated, which is a workshop task.
Possible causes
- The signal lead is short-circuited to ground
What you can do
- 1Check the connector to the oxygen sensor for loose connections and damage
- 2With the ignition off, use a multimeter to check that the signal lead from the oxygen sensor is not short-circuited to ground
- 3Look for chafing or pinch damage on the signal lead where it may have touched ground
- 4Have a workshop check the oxygen sensor during calibration if the fault remains after the wiring check
Symptoms you may notice1
- No noticeable symptoms for the driver
What the fault can affect1
- The engine control module uses the last measured value
General guidance for car owners. Diagnosis on the car can point to a different cause.