6162 doesn't use a thermocouple......the Spark Electrode provides high voltage to ignite the gas AND is used as return path for the flame signal that is a result of flame rectification
That signal is only a few milliamps
and doesn't take must to restrict it being sensed by circuit board
When was last time you CLEANED the burner assembly?
Propane system is only 11"WC (0.39psi) and has a narrow ignition range
Proper air/fuel ratio results in correct flame temp...clean spark electrode/wire connection provides reliable flame proving signal
Here is a Service Manual that has step by step testing procedures