K20 Engine Control Module (with AWD)

The K20 Engine Control Module monitors the AWD switch as an input. The K20 Engine Control Module applies 5 volts to the switch resistor ladder and monitors the signal voltage from the switch. As the switch is closed, current flows through different resistors and the voltage monitored at the K20 Engine Control Module also changes. The K20 Engine Control Module uses this voltage change to determine if the button is in the at rest position or has been pressed. The K20 Engine Control Module will change the drive mode based on this input.

When a drive mode change is requested by the drive through the AWD switch, the K20 Engine Control Module will broadcast a message to all modules indicating the requested drive mode. Control modules that are involved in changing their operation based on differing drive modes will then change their operating values.