What does P1299 mean on a Ford?

P1299. Cylinder Head Over-Temperature Protection Active. Applies to F-150, Super Duty, Mustang, Explorer with fail-safe cooling strategy.

What causes P1299 on a Ford?

Low coolant level from a leak in a hose, the radiator or the water pump Thermostat stuck closed, blocking coolant flow to the cylinder heads Cooling fan or fan clutch that does not engage as head temperature climbs Failed water pump or a slipping drive belt stopping coolant circulation Cylinder head temperature (CHT) sensor reporting a false over-temperature

How do I fix P1299 on a Ford?

Stop driving and let the engine cool fully. Fail-safe cooling alternately cuts fuel to cylinders to limit damage Check the coolant level and pressure test the hoses, radiator and water pump for leaks Verify the thermostat opens and the cooling fan engages as temperature rises Inspect the water pump and drive belt for wear or slip Test the CHT sensor only after the cooling system passes pressure and function checks Clear the code and retest after the repair to confirm fail-safe mode stays off

Code

P1299

Cylinder Head Over-Temperature Protection Active

Category: Powertrain - Fuel/Air Metering
Severity: Check Engine Light
Applies to: F-150, Super Duty, Mustang, Explorer with fail-safe cooling strategy
Related: P0217 Engine Coolant Over Temperature Condition on OBD Codes List

Findings, check these first

Low coolant level from a leak in a hose, the radiator or the water pump
Thermostat stuck closed, blocking coolant flow to the cylinder heads
Cooling fan or fan clutch that does not engage as head temperature climbs
Failed water pump or a slipping drive belt stopping coolant circulation
Cylinder head temperature (CHT) sensor reporting a false over-temperature

Standard procedure

Stop driving and let the engine cool fully. Fail-safe cooling alternately cuts fuel to cylinders to limit damage
Check the coolant level and pressure test the hoses, radiator and water pump for leaks
Verify the thermostat opens and the cooling fan engages as temperature rises
Inspect the water pump and drive belt for wear or slip
Test the CHT sensor only after the cooling system passes pressure and function checks
Clear the code and retest after the repair to confirm fail-safe mode stays off

Code lookup

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Sources and review

Review: checked against the recorded source material.

OBDII.pro: P1299 Ford definition
live reference page (obdii.pro)
Supports: Ford-family meaning for P1299: Cylinder Head Overtemperature Protection Active
Fetched directly. obdii.pro is a publisher independent of the engine-codes family.
P1299 FORD Code: Meaning, Causes, and Symptoms | OBD2 Codes
live reference page (obd2-codes.co)
Supports: Ford meaning for P1299: Cylinder Head Temperature Sensor Detected Engine Overheating Condition
Fetched directly. obd2-codes.co phrasing matches the engine-codes family, so it counts as one publisher.

Last updated 2026-10-10.

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