Cause of error code E65

Flue temperature sensor is shorted. '0' Ohm 

Solution for error code E65

1. Disconnect wire harness from vent temperature sensor. Measure sensor resistance. Does resistance match estimate flue temperature? 
Yes: -> 2
No: Replace vent temperature sensor. 

2. Disconnect harness from control module J5. Continuity in blue wires? 
Yes: Replace controle module.
No: Replace wires.