VOLVO
ECM-0037 - Rear 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)
What does this fault code mean?
The engine control module checks the heating of the rear oxygen sensor on bank 1 and treats incorrect voltage in the heater circuit as a fault. Common causes are a signal wire that is shorted or broken, and sometimes a damaged oxygen sensor.
Possible causes
- Signal cable shorted to supply voltage
- Signal cable shorted to ground
- Damaged rear oxygen sensor
What you can do
- 1With the ignition off, check the rear oxygen sensor contacts for looseness, contact resistance and oxidation
- 2With the connector unplugged and the ignition off, use a multimeter to check that the signal wire does not break when you move the harness
- 3Use a multimeter to check that the signal wire has no contact with ground (the body)
- 4If the fault remains after erasing codes and a test drive, although the wiring is sound, have a workshop check and replace the oxygen sensor if needed
Symptoms you may notice1
- Malfunction indicator lamp (MIL) lights up
General guidance for car owners. Diagnosis on the car can point to a different cause.