VOLVO
CEM-P046021 - Fuel Level Sensor A Circuit. General Signal Failures. Signal too low
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
Applies to the following models:
2 modelsV40 (2013–), V40 Cross Country (2013–)
Show models by year and engine (2)
What does this fault code mean?
The CEM monitors the direct voltage on the level sensor in the fuel pump. Here the voltage is too low, which comes from the sensor being shorted to earth. The fuel gauge and trip computer can then show too low a fuel level. The code does not name a specific fault type; it only describes the signal level.
Possible causes
- The fuel level sensor on the right-hand side is shorted to earth
What you can do
- 1Compare the fuel gauge with the trip computer and note whether it shows too low a level. Does it change when you refuel?
- 2Check the fuel pump and level sensor fuses in the engine bay and the CEM. If one has blown, check its circuit for a short to earth
- 3With a diagnostic tool, read the fuel level value in live data while the tank is filled and emptied. A value that stays still points to the sensor
- 4Use a multimeter to check that the wire to the fuel level sensor has no contact with earth or the body
- 5Check the connectors in the wiring to the fuel pump for corrosion and loose connections, but do not open the fuel system yourself
- 6Work on the fuel pump or tank is for a workshop, since petrol is flammable
Symptoms you may notice2
- The trip computer shows a wrong distance to empty
- The fuel gauge shows too low a value
General guidance for car owners. Diagnosis on the car can point to a different cause.