VOLVO
ECM-621C - Engine cooling fan (FC). Signal too high
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)
Show models by year and engine (9)
- Volvo C30 (2007–2013)2007Engine B5254T3 only
- Volvo C30 (2007–2013)2008–2013Engine B5254T7 only
- Volvo C70 (2006–2013)2006–2007Engine B5254T3 only
- Volvo C70 (2006–2013)2008–2013Engine B5254T7 only
- Volvo S40 (2004–2013)2005–2007Engine B5254T3 only
- Volvo S40 (2004–2013)2008Engine B5254T3, B5254T7 only
- Volvo S40 (2004–2013)2009–2012Engine B5254T7 only
- Volvo V50 (2004–2013)2005–2007Engine B5254T3 only
- Volvo V50 (2004–2013)2008–2012Engine B5254T7 only
What does this fault code mean?
The engine control module (ECM) has registered too high a signal on the signal cable to the cooling fan control module, and the code is set. This may be because the cable has come into contact with voltage, or because the control module is damaged.
Possible causes
- Signal cable short-circuited to supply voltage
- Damaged cooling fan control module
What you can do
- 1Use a multimeter to check that the signal cable is not in contact with battery voltage when the ignition is on
- 2Look for chafed cables that may have touched a live wire
- 3Check that the connectors to the fan and the control module are firmly seated and free from oxidation
- 4With a diagnostic tool: activate the cooling fan and check that it starts and stops as it should
- 5If you find no fault, have a workshop check the cooling fan control module
Symptoms you may notice1
- The cooling fan runs continuously even with the ignition switched off
General guidance for car owners. Diagnosis on the car can point to a different cause.