VOLVO
ECM-P048031 - Fan 1 Control Circuit. FM (Frequency Modulated) / PWM (Pulse Width Modulated) Failures. No signal
System
Engine Control Module (ECM)
Volvo models this fault code applies to
Applies to the following models:
2 modelsS80 (2007–), XC90 (2003–)
Show models by year and engine (2)
What does this fault code mean?
The engine control module (ECM) has registered that the PWM signal to the fan control module is outside its limits or missing, or that the fan control module is too hot. The fan may keep running for a while after the engine is switched off, which is normal. The code is general.
Possible causes
- Loose contact, contact resistance or oxidation in the connections
- Break in the power feed to the electric fan
- Signal wire short-circuited to supply voltage or to ground
- Open circuit in the signal wire
- Damaged electric fan, a blocked fan blade or a blocked fan motor
- Fault codes ECM-P048000, ECM-P048071 or ECM-P048068 can cause this code
What you can do
- 1With the ignition off, check that the fan blades turn freely and are not blocked
- 2Look at the fan fuse and make sure it is intact
- 3Check the connections to the electric fan for looseness, contact resistance and oxidation, and remedy as needed
- 4Use a multimeter to check that the signal wire is continuous and does not touch ground or supply voltage
- 5If you have a diagnostic tool, read the fault status with the ignition on to see whether the fault is active right now
- 6If the fault remains despite these checks, have a workshop examine the electric fan and its control
Symptoms you may notice1
- The electric fan does not work
General guidance for car owners. Diagnosis on the car can point to a different cause.