P1299 Ford and Lincoln: cylinder head over-temperature protection is active (the engine computer's fail-safe cooling mode)

Cylinder head over-temperature protection active (Ford/Lincoln)

P1299 in short

On Ford and Lincoln vehicles, P1299 means the engine computer saw severe overheating and switched to fail-safe cooling, cutting cylinders and limiting power. Low coolant, leaks, coolant entering a cylinder and some sensor or wiring faults are documented causes. Stop as soon as it is safe and let the engine cool.

Ford engines use a cylinder head temperature (CHT) sensor, and on some engines the coolant temperature sensor, to run a strategy Ford calls Fail Safe Cooling. As the engine overheats, the gauge moves to red and P1285 is set. If the driver keeps going, the computer cuts cylinders in rotation, drawing air through them to cool the engine, limits rpm, turns on the check engine light and sets P1299.

If the temperature keeps rising, the powertrain lamp flashes and the engine is switched off after about 30 seconds so you can find a place to stop. With P1299 still stored the engine may restart but stay limited to a very low rpm until a scan tool clears the code.

Most causes are real overheating, but Ford has bulletins where sensor wiring, CHT sensor software or generator interference set P1299 without a true overheat. Treat it as real until a technician confirms otherwise.

Pick your make

P1299 is a manufacturer-specific code: its meaning depends on who built the car.

Other makes: meaning not verified. Check with a scan tool that reads manufacturer definitions.

Most likely causes

  1. Low coolant or an external coolant leak

    Common general cause
    Why it ranks here
    Low coolant is the most common cause of overheating; Ford's fail-safe strategy exists for the case where coolant is lost.
    What would change this
    Rises if the reservoir is low or there are drips, steam or a sweet smell.

  2. Coolant leaking into a cylinder (1.5L and 2.0L EcoBoost)

    Supported by vehicle data
    Why it ranks here
    Ford lists P1299 with misfire codes, low coolant and white smoke on 1.5L and 2.0L EcoBoost engines where coolant enters a cylinder.
    What would change this
    Rises with falling coolant, no outside leak and white smoke at start-up.

  3. Machining debris blocking a coolant passage near the CHT2 port (2023-2025 Escape 1.5L)

    Supported by vehicle data
    Why it ranks here
    Ford found machining chips in the cylinder head of some Escapes built before 16-Sep-2024, causing over-temperature warnings with P1285/P1299 under hard acceleration.
    What would change this
    Rises on a covered Escape when the warning appears only under heavy load.

  4. CHT sensor or PCM software (2024-2025 F-150)

    Supported by vehicle data
    Why it ranks here
    Ford attributes P1299/P1285/P2C39 with an Engine Over-Temperature message on 2024-2025 F-150s to PCM software and/or the CHT sensor, with normal fan operation and no coolant loss.
    What would change this
    Rises on those trucks with full coolant and no real overheating.
    How to test the cylinder head temperature (cht) sensor

  5. ECT sensor wiring (2.7L EcoBoost) or generator interference (Transit Connect)

    Supported by vehicle data
    Why it ranks here
    Ford bulletins tie P1299 to ECT sensor or knock sensor harness faults on 2.7L EcoBoost engines and to generator interference on 2019-2020 Transit Connect.
    What would change this
    Rises if the warning appears suddenly with normal coolant and a cool engine on the listed models.
    How to test the engine coolant temperature (ect) sensor

  6. Cooling fan, thermostat or water pump failure

    Common general cause
    Why it ranks here
    Any part that stops heat leaving the engine can trigger the over-temperature strategy.
    What would change this
    Rises if the fan does not run or the upper radiator hose stays cool while the engine is hot.
    How to test the thermostat

What to test first

Start at step 1. Each result tells you what it means and where to go next.

  1. Stop safely, switch off and let the engine cool for at least 30 minutes. Do not open the coolant reservoir or radiator cap while hot.

    Low risk

    • IfSteam, a hot smell or the gauge was in the red

      It meansReal overheating; check coolant once cold.

      Go to step 2

    • IfWarning appeared suddenly with no steam or smell

      It meansPossibly a false reading on some models, but check coolant anyway.

      Go to step 2

  2. Once cold, check the coolant level and look for leaks under the car and around hoses.

    Use cautionTool: visual check

    Warning:Only with the engine fully cold; opening a hot cooling system can spray scalding coolant.

  3. Have a Ford dealer or shop check for bulletins on the VIN, compare CHT/ECT readings with actual temperature, test fan and thermostat operation, and run a combustion leak test.

    Best left to a shopTool: scan tool, pressure tester, block tester

    Warning:Cooling system tests involve hot, pressurised coolant and a running engine; leave them to a shop.

Symptoms

  • Temperature gauge in the red or an Engine Over-Temperature message Gets more serious: stop and have it checked.
  • Sudden loss of power or the engine running on fewer cylinders Gets more serious: stop and have it checked.
  • Powertrain lamp flashing, then the engine shuts off Gets more serious: stop and have it checked.
  • Low coolant or white exhaust smoke Gets more serious: stop and have it checked.

Compare with: Check engine light with loss of power

How to fix

We don't give DIY repair steps for a Stop code. Get the car inspected before you drive it; the tests above help you understand what a technician will check.

On your vehicle

Ford

  • 2014–2019 · 1.5L EcoBoost, 2.0L EcoBoost

    Supported by vehicle data

    On 1.5L and 2.0L EcoBoost Escape, Fusion and Edge, P1299 with misfire codes, low coolant or white smoke matches the coolant intrusion bulletins; the fix is a short block or long block.

  • 2023–2025 · Escape · 1.5L EcoBoost

    Supported by vehicle data

    On 2023-2025 Escape 1.5L built on or before 16-Sep-2024, over-temperature under hard acceleration can come from machining debris in a head coolant passage.

  • 2015–2025 · F-150

    Supported by vehicle data

    On F-150s, Ford has bulletins for false over-temperature warnings: ECT wiring on 2015-2020 2.7L EcoBoost and CHT sensor/PCM software on 2024-2025 trucks.

  • 17126Status unverified

    MIL with P1285 and/or P1299 (cylinder head over temperature), gauge reading hot or A/C inoperative

    2003focus · issued · NHTSA 10004047

    Ford bulletin for the 2003 Focus naming P1299 as cylinder head over temperature; the NHTSA summary does not give the repair.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • 20-2100Status unverified

    1.5L EcoBoost coolant intrusion with P0300-P0304, P0316, P0217, P1285, P1299

    2014–2019escape, fusion · 1.5L EcoBoost · issued · NHTSA 10174400

    Coolant enters a cylinder; replace the short block and head gasket. Supersedes 19-2139.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • 19-2172Status unverified

    2.0L EcoBoost coolant intrusion with P0300-P0304, P0316, P0217, P1285, P1299

    2015–2019edge, fusion, escape · 2.0L EcoBoost · issued · NHTSA 10162062

    Coolant enters a cylinder; replace the long block. Also covers Lincoln MKZ and MKC.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • SSM 54114Status unverified

    Engine Coolant Over-Temperature warning with P1285/P1299 under hard acceleration

    2023–2025escape · 1.5L EcoBoost · issued · NHTSA 11021705

    Machining chips in the cylinder head can block a coolant passage near the CHT2 port on 1.5L engines built on or before 16-Sep-2024; the message gives a diagnostic road test and flush.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • 26-2217Status unverified

    P1299, P1285 and/or P2C39 with Engine Over-Temperature message

    2024–2025f-150 · issued · NHTSA 11032695

    PCM software and/or the CHT sensor; diagnose and replace the CHT sensor with an updated version. Supersedes 24-2441.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • SSM 48991Status unverified

    MIL and/or Engine Coolant Over Temperature warning from the ECT or knock sensor harness

    2015–2020f-150, edge, fusion · 2.7L EcoBoost · issued · NHTSA 10177705

    On 2.7L EcoBoost engines, replace the ECT sensor and knock sensor harness. Also covers Lincoln MKX, Nautilus and Continental.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • 21-2168Status unverified

    MIL and/or Engine Coolant Over Temperature warning from an intermittent ECT voltage drop

    2018–2020f-150 · 2.7L EcoBoost · issued · NHTSA 10198582

    Fit the heater hose with relocated ECT sensor and a jumper harness.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • SSM 52786Status unverified

    False overheat with P1299 and/or P0217 from generator interference

    2019–2020transit-connect · issued · NHTSA 11006475

    If the concern stops with the generator disconnected, replace the generator.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Lincoln

  • 2015–2020

    Supported by vehicle data

    MKZ and MKC 2.0L EcoBoost are in the coolant intrusion bulletin; MKX, Nautilus and Continental 2.7L are in the ECT harness bulletin.

  • P0217The engine computer has detected an engine over-temperature condition

    Raises severity Supported by vehicle data

    P0217 records an engine over-temperature; on Fords P1299 is the next stage, when the computer starts cutting cylinders to protect the engine.

  • P0316A misfire was detected during the first 1,000 engine revolutions after start-up

    Shares causes Supported by vehicle data

    Ford lists P1299 with P0316 and other misfire codes when coolant leaks into a cylinder on 1.5L and 2.0L EcoBoost engines.

  • P0118Engine coolant temperature sensor circuit high

    Shares causes Supported by vehicle data

    On 2.7L EcoBoost engines Ford lists P0118 with P1299 when coolant temperature sensor wiring gives a false hot reading.

  • P1285Cylinder head temperature above the engine computer’s limit (Ford, Lincoln, Ford-built Mazda)

    Same system Supported by vehicle data

    P1285 (head over-temperature sensed) usually sets first, and many Ford bulletins cover P1285 and P1299 together.

All Engine cooling (thermostat) codes

P1299 questions

Why did my Ford lose power and run rough when the temperature went up?

That is Ford's fail-safe cooling: when the engine overheats, the computer cuts cylinders in rotation and limits rpm to cool the engine, and sets P1299. If it keeps getting hotter, the engine will shut off after the lamp flashes. Stop and let it cool.

Will the code clear itself after the engine cools?

Ford's manual says the reduced-power mode stays until the ignition is cycled, and in some cases until the code is cleared with a scan tool after the fault is fixed. Find the cause before clearing it.

Sources and review

  1. 2019 Ranger Workshop Manual 303-03 Engine Cooling 2.3L EcoBoost: Description and Operation (Fail Safe Cooling) — Ford Motor Company
  2. Ford TSB 17126: MIL with P1285 and/or P1299 (cylinder head over temperature), gauge reading hot or A/C inoperative — Ford Motor Company / NHTSA ,
  3. 2023 Integra Owner's Manual: How to Handle Overheating — American Honda Motor Co.
  4. Causes of Engine Overheating — AA1Car.com (Larry Carley, automotive technical writer)
  5. Ford TSB 20-2100: Coolant intrusion on 1.5L EcoBoost - low coolant, white smoke, rough running, P0300-P0304, P0316, P0217, P1285, P1299 — Ford Motor Company / NHTSA ,
  6. Ford TSB 19-2172: Coolant intrusion on 2.0L EcoBoost - low coolant, white smoke, rough running, P0300-P0304, P0316, P0217, P1285, P1299 — Ford Motor Company / NHTSA ,
  7. Ford SSM 54114: Engine Coolant Over-Temperature warning with P1285/P1299 under hard acceleration, 1.5L EcoBoost — Ford Motor Company / NHTSA ,
  8. Ford TSB 26-2217: P1299, P1285 and/or P2C39 with Engine Over-Temperature message, 2.7L — Ford Motor Company / NHTSA ,
  9. Ford SSM 48991: MIL and/or Engine Coolant Over Temperature warning from the ECT or knock sensor harness, 2.7L EcoBoost — Ford Motor Company / NHTSA ,
  10. Ford TSB 21-2168: MIL and/or Engine Coolant Over Temperature warning from an intermittent ECT voltage drop — Ford Motor Company / NHTSA ,
  11. Ford SSM 52786: False overheat with P1299 and/or P0217 from generator interference — Ford Motor Company / NHTSA ,
  12. Toyota Camry Owner's Manual (OM06291U, 2.5L A25A-FKS / 3.5L 2GR-FKS) — Toyota
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Saurabh K.
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