A919_O: PFC/DSP Comm Fault
On the VSODU, this fault would be displayed on the seven-segment LED as a number 15. A 15 displayed is one of several inverter faults. You will need to validate this fault at the EcoNet Thermostat or by looking at the red or yellow flashing LED's in the upper right quadrant of the drive itself
The Drive LED's will be flashing the Red LED 9 times.
This is an internal communication problem within the drive itself. It has nothing to do with your thermostat wiring. Check the mod-bus cable connections and Perform a hard reset of the drive and system to see if the problem goes away. Turn the power to the outdoor unit and the indoor unit off at the breakers and reapply power. If the problem persists, replace the drive.
