Controlling The Generator (Gen) (2005-)

Fig 1: Identifying Alternator Control Module (ACM), Engine Control Module (ECM) And Central Electronic Module (CEM) Communication

Courtesy of VOLVO CARS CORPORATION

The engine control module (ECM) (4/46) regulates the charge voltage of the generator (GEN) (via LIN communication) when requested by the central electronic module (CEM) (4/56) (via CAN communication).

The engine control module (ECM) can change the charge voltage requested by the central electronic module (CEM). to suit certain operating conditions such as engine start, idle speed or high engine load.

The value requested by the engine control module (ECM) for charging voltage and alternator charging current can be read using VIDA (Volvo scan tool).

The alternator control module (ACM) transmits fault information to the engine control module (ECM). Diagnostic trouble codes (DTCs) are stored in the engine control module (ECM).