VOLVO
ECM-552D - Oil temperature sensor. Signal too low
System
Engine Control Module (ECM)
Volvo models this fault code applies to
Applies to the following models:
4 modelsC30 (2007–2013), C70 (2006–2013), S40 (2004–2013), V50 (2004–2013)
What does this fault code mean?
The oil temperature is compared with the coolant temperature, and the code is set when the two differ too much. Although the code is named signal too low, the difference is what decides it. Because this value feeds the service interval, the fault can affect when the service indicator appears.
Possible causes
- Damaged oil temperature sensor
What you can do
- 1Clear the code and road test with the engine running to see whether it returns
- 2Check that the connectors at the oil and coolant temperature sensors are fully seated and free from oxidation and contact resistance
- 3With a multimeter, check that the oil temperature sensor's signal wire is not shorted to ground or voltage
- 4If you have a diagnostic tool, compare oil and coolant temperatures in live data after the engine has run a while and see whether the gap is unreasonable
- 5If the fault remains, have a workshop try a new oil temperature sensor
Symptoms you may notice1
- No noticeable symptoms for the driver
General guidance for car owners. Diagnosis on the car can point to a different cause.