Window Switch Operation
When any driver's door power window switch is pressed, a Simple Bus Interface (SBI) serial digital message is transmitted from the LH front power window switch to the Driver's Door Module (DDM). If the either the passenger or the rear window switch is pressed, an SBI message, relating the switch operation, is transmitted from the DDM to either the Passenger's Door Module (PDM) or the Rear Door Module (RDM) as appropriate. All of the window motors are directly controlled by their respective door modules.If the driver's window switch is pressed, the DDM will apply battery voltage of the correct polarity directly to the LH front power window motor, driving the window up or down.
Each window motor is protected by an electronic circuit breaker. If a window switch is held too long with the window obstructed or after the window is fully up or down, the circuit breaker opens the circuit. The circuit breakers have Positive Temperature Coefficients (PTC) and reset automatically when voltage is removed from the motors.