VOLVO
ECM-P250300 - Charging System Voltage Low. General Failure Information. No sub type information
System
Engine Control Module (ECM)
Volvo models this fault code applies to
Applies to the following models:
3 modelsS60 (2011–), S80 (2007–), V70 (2008–)
Show models by year and engine (9)
- Volvo S60 (2011–)2011–2012Engine B5254T5 only
- Volvo S80 (2007–)2007–2008Engine B5254T6 only
- Volvo S80 (2007–)2009Engine B5254T6, B5254T8 only
- Volvo S80 (2007–)2010–2011Engine B5254T10, B5254T11, B5254T8 only
- Volvo S80 (2007–)2012Engine B5254T10 only
- Volvo V70 (2008–)2008Engine B5254T6 only
- Volvo V70 (2008–)2009Engine B5254T6, B5254T8 only
- Volvo V70 (2008–)2010–2011Engine B5254T10, B5254T11 only
- Volvo V70 (2008–)2012Engine B5254T10 only
What does this fault code mean?
The alternator control module (ACM) reports to the engine control module when it detects an electrical fault in the generator, and the code is then stored. Worn carbon brushes or slip rings may be the cause. The code can also have been stored after a charger with excessive charge voltage was connected.
Possible causes
- A charger delivering excessive charge voltage was connected earlier
- Worn carbon brushes in the generator
- Damaged alternator control module (ACM, charge regulator)
- Damaged generator
What you can do
- 1If you have a diagnostic tool, read the battery voltage and the target value for the generator charge voltage with the engine running
- 2Switch on some high-current loads, such as the blower fan and high beam, and see whether the battery and charging cope
- 3If the battery and charging cannot cope, the fault is probably permanent; if they can, the fault may have been intermittent
- 4Have a workshop check the generator carbon brushes and slip rings; if they are worn, the control module or the generator must be replaced
- 5Ask yourself whether a battery charger has been connected to the battery before; a charger with too high charge voltage can cause this code
Symptoms you may notice5
- The "Generator not charging" warning lamp lights with the engine running
- The battery discharges
- The starter motor turns the engine slowly
- The electrolyte in the battery boils with the engine running
- The headlamp bulb blows
General guidance for car owners. Diagnosis on the car can point to a different cause.