P1299 Cylinder Head Overtemperature Protection Active : No Overheating

[syasar]

My 2014 ST goes into limp mode sometimes and throws P1299. The car by no means is overheating with coolant temperature around 100C - 110C. The code usually comes on after the car parked, never right in the middle of a drive. Already changed the ECT sensor, and the car doesn't actually have a CHT sensor to replace so the code is coming from the cylinder head actually overheating. This issue has been happening for over 5 years now, usually between more often during seasonal temperature changes when it get suddenly very hot or cold. I just learned to live with it, got the clear to code on the side of the road then get going and hope it does come up again and put the car in limp.

Where do I even start? Has anyone had this issue and resolved it.

I made a post about this a long time ago about the same issue.

Reference Post: https://www.fiestastforum.com/threa...rheating-how-do-i-test-the-signal-wire.27419/

 

[scooter123]

I would suggest that you drain the cooling system by removing the bottom radiator hose and then remount that hose. Then use a Vacuum filling device and fill the system per fords specific instructions. As for why, it may be that you have a large bubble of air trapped in your cylinder head.