LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Volvo >> 2004 >> S40 T-5, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Miscellaneous - Design And Function (544 Body) >> Engine Control Module (ECM) (B5244S4; 2004-2010) >> Function >> Controlling The Generator (Gen) (2005-)
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Controlling The Generator (Gen) (2005-)

Fig 1: Identifying Generator (GEN) (Alternator Control Module (ACM))
GLL146028Courtesy of VOLVO CARS OF NORTH AMERICA.

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).