2006 f150 not turning off

[Badinflpro]

When key is turned off motor will not go off for about 30 seconds or more. Replaced switch and did not help. Would like more solutions, PLEASE.

[boscoe99]

What happens when you pull the kill switch?

[Badinflpro]

Still won't shut off.

[Lobo48jim]

Does it make a noise like it is going on and off sputtering , sounds like timing could be advanced. No expert but I had a similar problem and it was the timing.

[Badinflpro]

No, it just keeps idling normal for a little while and then cuts off. Sometimes 10 seconds and sometimes 30 seconds.

[99yam40]

I believe some motors have to go through a shut down cycle when key is turned off before motor dies, but do not think it should take 30 seconds

[rodbolt17]

you either have a bad ground connection, a main relay sticking or the ECU is going south.
the ECU has to cycle down and reset the ISC valve at shutdown.

[Badinflpro]

Thank you for the replies, I'll check all ground connections and main relay. Hope it's not the ECU.