Charge Mode

The BCM will enter Charge Mode when ever one of the following conditions are met.

• The wipers are ON for than 3 seconds.
• GMLAN (Climate Control Voltage Boost Mode Request) is true, as sensed by the HVAC control head. High speed cooling fan, rear defogger and HVAC high speed blower operation can cause the BCM to enter the Charge Mode.
• The estimated battery temperature is less than 0°C (32°F).
• Battery State of Charge is less than 80 percent.
• Vehicle speed is greater than 145 km/h (90 mph)
• Current sensor fault exists.
• System voltage was determined to be below 12.56 V

When any one of these conditions is met, the system will set targeted alternator output voltage to a charging voltage between 13.9-15.5 V, depending on the battery state of charge and estimated battery temperature.