T904_O: DC Bus Overvoltage
On the VSODC, this fault would be displayed on the seven-segment LED as a number 15. Keep in mind, a 15 is an inverter fault, but does not specify any particular inverter fault. You will need to read the exact fault at the EcoNet thermostat or by looking for a yellow flashing LED in the upper right quadrant of the drive itself.
The Drive LED's will be flashing the yellow LED 7 times.
This fault is generally not going to be seen in the field. The DC Bus voltage is produced based on incoming AC voltage and one would expect a AC voltage fault to occur before this one does. In a rare case one might thing, some sort of power event at the home could have taken place, but there would likely be more faults than this one.
Cycle power to both the Outdoor unit and the Indoor unit
