VOLVO
CEM-3A04 - Fuel pump. Signal too high. Intermittent fault
System
Central Electronic Module (CEM)
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:
5 modelsS60 (2001–2009), S80 (1999–2006), V70 (2000–2008), V70 XC / XC70 (2001–2007), XC90 (2003–)
What does this fault code mean?
The CEM has at some point registered a signal that is too high. The fault is intermittent, so it may have occurred before without being active now. The usual cause is a short to plus or a defective relay, and the fuel pump may sound louder than usual.
Possible causes
- A short to positive supply
- A defective relay
What you can do
- 1Check the fuel pump fuse. If it has blown, replace it once. If it blows again, use a multimeter to check the wire after it has no contact with ground
- 2Check that the fuel pump relay is seated correctly and that its contacts are not corroded
- 3Use a multimeter to check that the wire between the CEM and the fuel pump has no short to positive supply
- 4After the work, clear the code and check that the fuel pump does not sound unusual
Symptoms you may notice2
- Noise from the fuel pump
- Noise from the engine compartment
General guidance for car owners. Diagnosis on the car can point to a different cause.