Whirlpool AKZ161/03/1X oven error 03

Hi

Whirlpool AKZ161/03/1x built in double oven error code E3

Looking on here/internet seems to be either oven temp sensor or power board.

Tests /work done so far

Replace oven fan element,almost dead short on original element.

Check all components seem to working fine .

Remove and refit all wires and plugs.

Oven works “every single time for approx 2.5 minutes” then throws up error 03

switch oven off at the wall then straight back on and NO error 03 then watch it work for another 2.5 mins again.(you could do this forever)

Removed temp sensor wiring from pcb creates error 01 slaved a thermistor on again error 01.

resistance readings on temp sensor seem to altering as oven was cooling down.

Have not checked what temp oven is reaching,suggestions on internet say may be getting too hot.was going to go back and try a thermometer in there.

Any thoughts???

Colly