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Home >> Ford >> 2015 >> Explorer Limited, 3.5L Eng VIN 8, AWD >> Repair and Diagnosis >> Heating, Ventilation & A/C (HVAC) >> HVAC Control Systems >> Climate Control - EMTC >> Diagnosis And Testing >> Climate Control System >> Pinpoint Tests >> PINPOINT TEST J : Insufficient, Erratic or No Heat >> PINPOINT TEST J : Insufficient, Erratic or No Heat

PINPOINT TEST J : Insufficient, Erratic or No Heat

NOTE: Restriction of air flow through the radiator or Air Conditioning (A/C) condenser by an external obstruction such as leaves or cardboard can cause erratic operation.
NOTE: Missing or broken engine coolant hose check valve or incorrect orientation of check valve (if equipped) can cause poor heater performance at idle.

  1. J1 CHECK FOR CORRECT ENGINE COOLANT LEVEL

    NOTE: Allow the engine to cool before checking the coolant level.
    • Ignition OFF.
    • Visually check the engine coolant level in the degas bottle.

    Is the engine coolant at the correct level as indicated on the engine coolant recovery reservoir? 

    Yes  For 3.5L Ti-VCT, GO to  J2. For 3.5L GTDI, GO to  J3. All other engines, GO to  J4.
    No  Go to Pinpoint Test A .

  2. J2 CHECK THE ENGINE COOLANT VENT HOSE CHECK VALVE

    NOTE: Do not apply more than 96 kPa (14 psi) compressed air to the vent hose check valve, or the valve may be damaged.
    • Disconnect the engine coolant vent hose from the degas bottle and the thermostat housing.
    • Using regulated compressed air, confirm air flows freely from the engine end to the degas bottle end.
    • Using regulated compressed air, confirm air does not flow from the degas bottle end to the engine end.

    Does air flow through in one direction and not the other? 

    Yes  GO to  J4.
    No  INSTALL a new hose (base part number 8276). TEST the system for normal operation.

  3. J3 CHECK THE ENGINE COOLANT VENT HOSE CHECK VALVE

    NOTE: Do not apply more than 96 kPa (14 psi) compressed air to the vent hose check valve, or the valve may be damaged.
    • Remove the upper radiator hose.
    • Using hose pinch pliers, clamp the upper radiator hose near the degas bottle hose connection on the side of the upper radiator hose that leads to the radiator.
      NOTE: Use shop towels to seal the end of the upper radiator hose where regulated compressed air is applied.
    • Using regulated compressed air, confirm air flows freely from the upper radiator hose end to the degas bottle end.
    • Using regulated compressed air, confirm air does not flow from the degas bottle end to the upper radiator hose end.

    Does air flow through in one direction and not the other? 

    Yes  GO to  J4.
    No  INSTALL a new hose (base part number 8260). TEST the system for normal operation.

  4. J4 CHECK FOR COOLANT FLOW TO THE HEATER CORE

    NOTE: Missing or broken engine vent hose check valve or incorrect orientation of check valve (if equipped) can cause poor heater performance at idle.
    • Run the engine until it reaches normal operating temperature. Select the floor position. Set the temperature control to full warm and the blower to the lowest setting.
    • Using a suitable temperature measuring device, check the heater core inlet hose to see if it is hot.

    Is the heater core inlet hose temperature above 66°C (150°F)? 

    Yes  GO to  J5.
    No  Go to Pinpoint Test C .

  5. J5 CHECK FOR A PLUGGED OR RESTRICTED HEATER CORE

    • Using a suitable temperature measuring device, measure the heater core outlet hose temperature.

    Is the heater core outlet hose temperature similar to the inlet hose temperature (within approximately 6°C (43°F) - 17°C (63°F))? 

    Yes  DIAGNOSE the temperature blend door actuator. GO to Pinpoint Test N 
    No  INSTALL a new heater core. REFER to Climate Control - DATC .
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