P1299
Cylinder Head Overtemperature Protection Active
Get Your FREE AI Diagnostic Report
Enter your vehicle for a personalized diagnosis for code P1299
The P1299 is a critical Ford-specific code indicating that the Powertrain Control Module has activated its fail-safe cooling strategy because the cylinder head temperature has exceeded safe operating limits. When this code is triggered, the PCM takes emergency action: it reduces engine power, shuts off the air conditioning compressor (to reduce engine load), runs the cooling fans at maximum, and may even shut down cylinders to prevent catastrophic engine damage.
This code should be taken very seriously. If your engine is genuinely overheating, continuing to drive can cause warped cylinder heads, a blown head gasket, or even a seized engine — repairs that can cost thousands of dollars. Pull over safely, turn off the engine, and let it cool completely before checking the coolant level. Look under the vehicle for signs of coolant leaks (green, orange, or pink fluid).
However, it's worth noting that in some Ford vehicles, a faulty CHT sensor can trigger this code even when the engine isn't actually overheating. If you've verified that the coolant level is correct, the fans are working, and there are no visible leaks, have the CHT sensor tested. Common underlying causes include a stuck thermostat, a failing water pump, a cracked radiator hose, or a blown head gasket. Have the vehicle towed to a mechanic rather than driving it if there's any doubt about the actual temperature.
Severity
Symptoms
- •Engine power is severely reduced (fail-safe cooling mode)
- •Temperature warning light is illuminated
- •Check engine light is on
- •Engine may stall or shut down at idle
- •Cooling fans running at maximum speed
- •Air conditioning is disabled
Likely Causes
A leak in the cooling system — from a hose, radiator, water pump, or head gasket — reduces coolant volume and causes the engine to overheat.
A thermostat that is stuck in the closed position prevents coolant from flowing to the radiator, causing rapid overheating.
A water pump with a broken impeller or failed bearing cannot circulate coolant through the engine, leading to overheating.
In some cases, the CHT sensor itself may be faulty and reporting overtemperature when the engine is not actually overheating.
Estimated Cost
Professional Repair
Includes parts + labor
Common Fixes
- Check coolant level immediately and top off if low
- Inspect the cooling system for leaks (hoses, radiator, water pump, heater core)
- Replace the thermostat if stuck closed
- Replace the water pump if it has failed
- Replace the CHT sensor if giving false high readings