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Home >> Ford >> 2018 >> Taurus Limited, FWD, Gas >> Repair and Diagnosis >> External Pages >> Different car >> Section 92 (Engine Cooling - 1.0L ECOBOOST (92KW/125PS)) >> Diagnosis And Testing >> Engine Cooling >> Pinpoint Tests >> Pinpoint Test B : The Engine Overheats

Pinpoint Test B : The Engine Overheats

WARNING: This page is about a different car, the 2018 Ford EcoSport. However, it is still accessible from the selected car via links, so may be relevant.
  1. Normal Operation and Fault Conditions 

    The engine cooling system maintains the engine temperature during operation. Correct coolant flow through the engine, radiator and remainder of cooling system passages and components is essential to maintaining a correct engine temperature.

    Engine coolant flows primarily from the engine to the radiator circuit and back to the coolant pump. Coolant is sent from the coolant pump through the engine block and cylinder heads. A separate circuit from the engine also feeds the heater core with coolant. The coolant pump circulates the coolant. The coolant thermostat is a control valve actuated by coolant temperature. When the thermostat is closed, coolant flow bypasses the radiator circuit and returns to the coolant pump. When the thermostat is opened, coolant flows through the radiator circuit to transfer engine-generated heat to the outside air. This engine also incorporates an additional cylinder block thermostat to control a mini coolant circuit. When the cylinder block thermostat closed coolant only flows through the exhaust side of the cylinder head. From here the coolant arrives at the oil cooler via the heater core and from there it is passed to the coolant pump. In this phase there is no coolant flow in the cylinder block nor on the intake side of the cylinder head. This leads to rapid warm-up of the engine and the engine oil, through which the friction at the lubrication points is reduced at an early stage. When the cylinder block thermostat opens coolant flows through the cylinder block and intake side of the cylinder head similar to a conventional cooling system.

    Engine overheating generally occurs when there is a disruption in the ability to control either coolant flow at the correct rate, the inability to transfer heat from the engine through the coolant (including low coolant) or an inability to transfer engine-generated heat to the outside air through the radiator.

    DTC Fault Trigger Conditions 

    DTC Description Fault Trigger Condition
    PCM P0217:00 Engine Coolant Overtemperature Condition: No Sub Type Information Indicates an engine overheat condition was sensed by the CHT sensor or the ECT sensor
    PCM P1285:00 Cylinder Head Overtemperature Condition: No Sub Type Information Indicates an engine overheat condition was sensed by the CHT sensor or the ECT sensor
    PCM P1299:00 Cylinder Head Overtemperature Protection Active: No Sub Type Information Indicates an engine overheat condition was detected by the CHT sensor or the ECT sensor. A failure mode effects management strategy called fail-safe cooling was activated to cool the engine.

    Possible Sources 

    • Low coolant level
    • External engine coolant leak
    • Airlock in system
    • Pressure relief cap installation
    • Restricted airflow through A/C condenser/radiator
    • Internal engine coolant leak
    • Coolant condition/concentration
    • Accessory drive components
    • Non-OEM engine enhancement components
    • Electric cooling fan
    • Engine temperature gauge
    • ECT sensor
    • Heater core
    • Coolant pump
    • Coolant flow restriction
    • Turbocharger
    • Radiator
    • Thermostat
    • Cylinder block thermostat
    • Transmission fluid cooler
    • Transmission fluid warmer

    Visual Inspection and Pre-checks 

    • Fuse(s)
    • Accessory drive belt
    • Hoses

  2. B1 CARRY OUT INSPECTION AND VERIFICATION

    • Carry out the Inspection and Verification procedure in this article.

    Are any concerns present? 

    Yes  REPAIR as needed.
    No  GO to  B2

  3. B2 CHECK FOR PCM (POWERTRAIN CONTROL MODULE) DTCS

    • Ignition ON.

    • Using a scan tool, perform PCM self-test.

    Is DTC P0217, P1285, or P1299 present? 

    Yes  GO to  B3
    No  Actual engine overheating has not been verified. CHECK the engine coolant temperature gauge operation. REFER to: Instrumentation, Message Center and Warning Chimes . If any other PCM DTCs are retrieved, REFER to: Electronic Engine Controls .

  4. B3 CHECK FOR AN AIRFLOW OBSTRUCTION AND MISSING AIR DEFLECTORS

    NOTE: Verify no vehicle front end damage is present.

    • Check the radiator or A/C condenser for an external obstruction such as leaves or cardboard and verify all air deflectors are present.

    Is an airflow obstruction present or air deflectors missing? 

    Yes  REPAIR as necessary.
    No  GO to  B4

  5. B4 CHECK THE ECT (ENGINE COOLANT TEMPERATURE) AND AMBIENT AIR TEMPERATURE CORRELATION

    • Check temperature values while engine is at ambient temperature, cold soak the engine for a minimum of 6 hours if necessary. Make sure the vehicle has not been in direct sunlight.

    • Using a diagnostic scan tool, monitor the PCM ECT (TEMP) and AAT (TEMP) PIDs.

    Are the temperature readings within 10 degrees of each other? 

    Yes  If the vehicle is equipped with active grill shutters, GO to  B5. If the vehicle is not equipped with active grill shutter, GO to  B6
    No  INSTALL a new ECT sensor, REFER to: Engine Coolant Temperature (ECT) Sensor .

  6. B5 CHECK THE ACTIVE GRILL SHUTTER OPERATION

    • Start the engine and allow it to idle for at least 30 seconds to allow for the grille shutter calibration to complete.

    • Using a diagnostic scan tool, view PCM Parameter Identifications (PIDs).

    • Using a scan tool, select the PCM Parameter Identification (PID) GRILL_A_CMD and active command the grille shutter from 100% (open) to 0% (closed) while observing the grille shutter operation from the front of the vehicle.

    Does the grille shutter fully open and close when commanded by the scan tool? 

    Yes  GO to  B6
    No  Diagnose the active grille shutter is inoperative or does not operate correctly, REFER to: Active Grille Shutter .

  7. B6 CHECK THE ELECTRIC COOLING FAN OPERATION

    • Start the engine.

    • Place the climate control function selector in the MAX A/C position and the blower motor switch in the HI position.

    Did the electric cooling fan operate? 

    Yes  GO to  B7
    No  DIAGNOSE the electric cooling fan operation. Refer to ENGINE CONTROLS - SYMPTOM CHARTS (EXCEPT DIESEL & HYBRID) .

  8. B7 PRESSURE TEST THE DEGAS BOTTLE CAP

    • Ignition OFF.

    Does the cap pass the pressure test? 

    Yes  GO to  B8
    No  INSTALL a new cap. If the engine overheat concern persists GO to  B8

  9. B8 CHECK THE ENGINE COOLANT LEVEL AND PRESSURE TEST THE ENGINE COOLING SYSTEM

    NOTE: Allow the engine to cool before checking the engine coolant level.

    • Ignition OFF.

    • Visually inspect the engine coolant level at the degas bottle and adjust as necessary. Pressure test the engine cooling system. Refer to Cooling System Pressure Test 

    Does the pressure maintain 124 - 138 kPa (18 - 20 PSI) for a minimum of 2 minutes? 

    Yes  GO to  B13
    No  For external coolant leaks REPAIR or INSTALL new components. If no external leaks are present GO to  B9

  10. B9 CHECK THE ENGINE COOLANT FOR AN INTERNAL LEAK

    • Inspect the engine coolant in the coolant expansion tank for signs of engine oil.

    Is engine oil evident in the coolant? 

    Yes  REFER to: Engine .
    No  GO to  B10

  11. B10 CHECK THE ENGINE OIL FOR COOLANT

    • Remove the oil level indicator from the engine.

    Is coolant evident in the oil? 

    Yes  REFER to: Engine .
    No  GO to  B11

  12. B11 CHECK THE ENGINE COOLANT FOR TRANSMISSION FLUID

    • Check the engine coolant in the degas bottle for signs of transmission fluid.

    Is coolant evident in the oil? 

    Yes  REFER to: Engine .
    No  GO to  B12

  13. B12 CHECK THE TRANSMISSION FLUID FOR ENGINE COOLANT

    • Remove the transmission oil leveling plug.

    1. GFD326080Courtesy of FORD MOTOR COMPANY

    • Check the transmission fluid for engine coolant.

    Is engine coolant evident in the transmission fluid? 

    Yes  INSTALL a new Transmission Fluid Cooler and Transmission Fluid Warmer. REFER to: Transmission Fluid Cooler - 1.0L EcoBoost (92kW/125PS) . REFER to: Transmission Fluid Warmer . REPAIR the transmission as necessary. REFER to: Transmission Cooling . TEST the system for normal operation.
    No  GO to  B13

  14. B13 CHECK THE COOLING SYSTEM FOR COMBUSTION GASES

    NOTE: Use UView Combustion Leak Tester part number UVU560000-R or equivalent.

    • Using a cooling system combustion gas leak tester, following the instructions supplied with the tester, check the coolant for combustion gases.

    Are combustion gases present? 

    Yes  REFER to: Engine .
    No  GO to  B14

  15. B14 VISUALLY INSPECT THE THERMOSTAT

    Is the thermostat damaged? 

    Yes  INSTALL a new thermostat housing. REFER to: Thermostat Housing .
    No  INSTALL a new thermostat housing. REFER to: Thermostat Housing . If the engine still overheats, GO to  B15

  16. B15 VISUALLY INSPECT THE CYLINDER BLOCK THERMOSTAT

    Is the cylinder block thermostat damaged? 

    Yes  INSTALL a new cylinder block thermostat. REFER to: Cylinder Block Thermostat .
    No  INSTALL a new cylinder block thermostat. REFER to: Cylinder Block Thermostat . If the engine still overheats, INSTALL a new radiator. REFER to: Radiator .
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