GM Service Manual Online
For 1990-2009 cars only

Generator Control Module

The generator control module, also referred to as the starter generator control module, is a serviceable GMLAN device located under the hood, toward the front of the vehicle on the drivers side. It is connected to the vehicles 12 and 36-volt DC power circuits, and it is also joined to the starter-generator by 3-phase AC cables. The generator control module is cooled by engine coolant, which is circulated through a cold plate. A separate, electrically driven pump is used to ensure adequate coolant flow, and individual coolant inlet and outlet hoses connect the cold plate to the cooling system.

Generator Control Module Coolant Pump

The generator control module coolant pump is a serviceable component which is connected to the vehicle cooling system and the module cold plate using separate, serviceable hoses. The pump augments the engine driven water pump to ensure adequate coolant flow to the cold plate.

Generator Battery Vent Fan

The generator battery vent fan is a serviceable component attached to the rear of the generator battery carrier assembly. This variable speed fan is controlled and powered by the generator battery disconnect control module. The fan draws cooling air through the bottom of the generator battery carrier assembly, exhausting it to the exterior of the vehicle. Fan speed is varied, as required, to ensure that generator battery temperature remains within desired limits.