VOLVO
ECM-1420 - Generator. No signal
System
Engine Control Module (ECM)
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:
3 modelsC30 (2007–2013), S40 (2004–2013), V50 (2004–2013)
What does this fault code mean?
The fault concerns the alternator control signal, which the engine control module (ECM) sends as a PWM signal. Although the fault says the signal is missing, it can also be set when the signal is too high or too low, or when the alternator gets too hot.
Possible causes
- Play, contact resistance or oxidation in the connections
- Open circuit in the signal wire
- Signal wire shorted to ground
- Clogged ventilation in the alternator housing
- Damaged alternator
What you can do
- 1Read the fault code, clear it and test drive to see whether it returns
- 2Check the alternator connector for play, contact resistance and oxidation
- 3Check the alternator control signal wire for breaks
- 4Check that the alternator housing is not clogged with dirt, so that air can circulate through the alternator
- 5If nothing is found and the fault code returns after clearing and a test drive: have a workshop try a new charging regulator
Symptoms you may notice1
- No noticeable symptoms for the driver
General guidance for car owners. Diagnosis on the car can point to a different cause.