VOLVO
ECM-8300 - Alternator control module (ACM). Faulty
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 communicates with the generator's control module (ACM). The fault code is set when the generator's control module reports that the generator is too hot, or that there is a mechanical fault, for example the generator standing still while the engine is revving. The fault applies to the C30, C70 (06-), S40 (04-) and V50.
Possible causes
- Defective auxiliaries belt or belt tensioner
- Damaged freewheel
- Damaged generator
- Air intake or air outlet to the generator is blocked
What you can do
- 1Check that the drive belt and the belt tensioner are not damaged
- 2Check that the air intake and air outlet to the generator are not blocked
- 3Check the generator freewheel: the rotor shaft should turn freely in one direction only
- 4If you have a diagnostic tool: read the generator temperature in live data, if available, and see whether it rises unreasonably
- 5If the code is set again after driving, have a workshop replace the generator
Symptoms you may notice4
- The "Generator not charging" warning lamp comes on while the engine runs
- The battery discharges
- Noise from the generator or the belt
- The engine judders under acceleration
General guidance for car owners. Diagnosis on the car can point to a different cause.