VOLVO
ECM-830C - Alternator control module (ACM). Faulty signal
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 has received word from the central electronic module (CEM) that the voltage in the power supply has been too high. The code is always stored together with another power supply fault code. The cause may be a battery charger with too high a charge voltage that was connected earlier, or a damaged generator control module. The fault applies to the C30, C70 (06-), S40 (04-) and V50.
Possible causes
- A battery charger with too high a charge voltage was connected earlier
- Damaged generator control module (charge regulator)
What you can do
- 1Start the engine and read the battery voltage
- 2Load the battery with a few large consumers, such as the blower and high beam, and note whether the voltage becomes normal
- 3If you have a diagnostic tool: compare the battery voltage with the generator's target charge voltage
- 4Ask whether a battery charger with too high a charge voltage has been connected to the car in the past
- 5If the fault remains, have a workshop check the generator's carbon brushes and slip rings and, if needed, replace the control module or the generator
Symptoms you may notice2
- The electrolyte in the battery boils when the engine runs
- The headlamp bulb blows
General guidance for car owners. Diagnosis on the car can point to a different cause.