Electrical Load Management

The ATC module manages the vehicle electrical loads to:

• Maintain the vehicle battery in a healthy state of charge.
• Ensure adequate power is available for defrost demisting during engine warm-up.
• Ensure adequate power is available for A/C during extended periods with the engine at idle speed.
• To maintain system voltage within acceptable limits.
• To provide adequate power to meet customer expectations.

Electrical load management is achieved by increasing the engine idle speed and controlling the electrical load of systems that do not affect the driveability or safety of the vehicle.

During the engine warm-up period, the ATC module manages the electrical load to make sure that the battery voltage is maintained above a pre-determined level. The battery voltage level that is maintained and the duration of the start period varies with ambient air temperature and ECT (engine coolant temperature). After the engine warm-up period, the ATC module manages the electrical load to make sure that the requested electrical load does not exceed the generator output.

The duration of the engine warm-up period depends on the ambient air temperature and the ECT, as detailed in the following table: