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.

 

[14BeanST]

@syasar I also own a 14 ST and Ive been experiencing this issue for a few years as well. I'm on the east coast and notice that the car wont go into limp mode during the winter seasons but as soon as it warms up it will start acting up again. I'm thinking that Ford might've butchered my last coolant flush and i have an air bubble in the system. If it isn't that then it has to be electrical but i already replaced the Coolant temp sensor. If you found a solution to your problem let me know!

 

[madhatter]

Bleeding these cars isn't that difficult. what is the level in the overflow resivoir? have you had the recall done?

 

[14BeanST]

Yup the recall was done on my car. When I got the car back from ford it was full but when I drove the car home and checked it was below min so I filled it up with fords yellow coolant. Maybe some air got into the system on the drive back home but I haven’t had real heating issues with the car. I’m gonna bleed the system today and see if that helps.