VOLVO
CEM-P134621 - Fuel Level Sensor B 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?
On the V40 the CEM checks the direct voltage from the sensor on the ejector side. The reading is too low, which comes from the sensor being shorted to earth. The fuel gauge can then show too low a value, and the distance-to-empty figure in the trip computer becomes wrong.
Possible causes
- The sensor on the ejector side is shorted to earth
What you can do
- 1Compare the fuel gauge with the trip computer over a normal journey. Do the readings 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
- 3Use a multimeter to check that the wire to the sensor on the ejector side has no contact with earth or the body
- 4With a diagnostic tool, read the fuel level value in live data. If it stays still while the tank is filled or emptied, the sensor is suspect
- 5Check the connectors in the wiring for corrosion and loose connections. Do not open the fuel system yourself
- 6Replacing the sensor or the fuel pump is done by a workshop, since the fuel system 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.