Cause of error code E57

Flue sens open.

Solution for error code E57

1. Is harness plugged into Vent Temperature Sensor? Is harness plugged into Control Module J5? 
Yes: -> 2.
No: Insert harness

2. Disconnect harness from Vent Temperature Sensor and Control Module J5. Continuity for each blue wire? 
Yes: ->3. 
No: Replace wires.

3. Measure resistance across Vent Temperature Sensor terminals. Does resistance match estimated flue temperature? 
Yes: Replace Control Module. 
No: Replace Vent Temperature Sensor.