Engine Cooling System: Diagnosis Ford Taurus IV рестайлинг

Inspection and Verification

Note. The addition of Motorcraft Cooling System Stop Leak Pellets, VC-6, darkens Motorcraft Premium Gold Engine Coolant from yellow to golden tan.

1. Verify the customer's concern by operating the engine to duplicate the condition.
2. Inspect to determine if any of the following mechanical or electrical concerns apply. VISUAL INSPECTION CHART Mechanical Electrical Leaks Restricted airflow coolant through the condenser/radiator Damaged hoses Loose/damaged hose clamps Damaged gasket Damaged head gaskets Damaged intake manifold gasket Damaged coolant pump Damaged radiator Damaged degas bottle Damaged heater core Damaged engine coolant temperature (ECT) sensor Damaged wiring Electric cooling fans Fuse Relay(s) Circuitry
3. If the inspection reveals an obvious concern that can be readily identified, repair it as necessary.
4. Inspect the coolant condition. Inspect the coolant color: NOTE: The addition of Motorcraft Cooling System Stop Leak Pellets, VC-6, darkens Motorcraft Premium Gold Engine Coolant from yellow to golden tan. If Motorcraft Premium Gold Engine Coolant VC-7-A (in California and Oregon VC-7-B, in Canada VC-7-C) or equivalent meeting Ford specification WSS-M97B51-A1 (yellow color) has a clear or pale yellow color, this indicates higher water content than required. Dark brown can indicate unauthorized stop leak may have been used. Use Motorcraft Cooling System Stop Leak Pellets VC-6 or equivalent meeting Ford specification WSS-M99B37-B6 only. A light or reddish brown color indicates that rust may be present in the cooling system. Flush the system and refill with the correct mixture of clean distilled water and engine coolant. An iridescent sheen on top of the coolant can indicate a trace of oil is entering the system. For additional information on engine diagnosis, refer to «ENGINE SYSTEM-GENERAL INFORMATION»(ref-233705) . A milky brown color may indicate that either engine oil or transmission fluid is entering the cooling system. If transmission fluid is suspected the cause may be a leaky radiator, pressure test the cooling system. Refer to «COMPONENT TESTS»(ref-233700-S39988562332006052600000) . If engine oil is suspected, the cause of the leak may be internal to the engine. For additional information on engine diagnosis, refer to «ENGINE SYSTEM-GENERAL INFORMATION»(ref-233705) . If transmission fluid is contaminated with engine coolant the cause may be a leaky radiator, pressure test the system. Refer to the «COMPONENT TESTS»(ref-233700-S39988562332006052600000) . If the engine coolant appearance is acceptable, test the engine coolant freezing point range with the Battery/Anti-Freeze Tester. The freezing point should be in the range -50°F to -10°F. If the vehicle is driven in cold climates less than -34°F, it may be necessary to increase the coolant concentration to get adequate freeze protection. Maximum coolant concentration is 60/40. Minimum coolant concentration is 40/60. Adjust coolant range and level if necessary: If coolant is low, add specified coolant mixture only. If the engine coolant tests too weak, add straight engine coolant until the readings are within acceptable levels. If the engine coolant tests strong, remove some of the engine coolant and add clean distilled water until the readings are within acceptable levels.
5. Verify the cooling system is correctly filled and bled. Refer to «COOLING SYSTEM DRAINING, FILLING AND BLEEDING»(ref-233700-S21960513852006052600000) .
6. If DTC P1474, P1477 or P1479 are present, See «INTRODUCTION - GASOLINE»(ref-229953) for diagnosis.
7. If the concern remains after the inspection, determine the symptom(s). GO to «SYMPTOM CHART»(ref-233700-S27364983742006052600000) .

Symptom Chart

PROBLEM SYMPTOM CHART

PINPOINT TEST A: LOSS OF ENGINE COOLANT

1. A1 CHECK THE ENGINE COOLANT LEVEL WARNING: Never remove the pressure relief cap while the engine is operating or when the cooling system is hot. Failure to follow these instructions can result in damage to the cooling system or engine or personal injury. To avoid having scalding hot coolant or steam blow out of the degas bottle when removing the pressure relief cap, wait until the engine has cooled, then wrap a thick cloth around the pressure relief cap and turn it slowly. Step back while the pressure is released from the cooling system. When you are sure all the pressure has been released, turn and remove the pressure relief cap (still with a cloth). NOTE: Allow the engine to cool before checking the engine coolant level. Key in OFF position. Visually check the engine coolant level at the degas bottle. Is the engine coolant level within specification? Yes : GO to A2 . No : REFILL the engine coolant as necessary. GO to A2 .
2. A2 INSPECT THE DEGAS BOTTLE PRESSURE RELIEF CAP WARNING: Never remove the pressure relief cap while the engine is operating or when the cooling system is hot. Failure to follow these instructions can result in damage to the cooling system or engine or personal injury. To avoid having scalding hot coolant or steam blow out of the degas bottle when removing the pressure relief cap, wait until the engine has cooled, then wrap a thick cloth around the pressure relief cap and turn it slowly. Step back while the pressure is released from the cooling system. When you are sure all the pressure has been released, turn and remove the pressure relief cap (still with a cloth). Remove the pressure relief cap. Inspect the pressure relief cap for foreign material between the sealing gasket and the diaphragm. Test the pressure relief cap. Refer to «COMPONENT TESTS»(ref-233700-S39988562332006052600000) . Is the pressure relief cap OK? Yes : GO to A3 . No : CLEAN or INSTALL a new pressure relief cap. TEST the system for normal operation.
3. A3 CHECK THE ENGINE COOLANT FOR INTERNAL LEAK WARNING: Never remove the pressure relief cap while the engine is operating or when the cooling system is hot. Failure to follow these instructions can result in damage to the cooling system or engine or personal injury. To avoid having scalding hot coolant or steam blow out of the degas bottle when removing the pressure relief cap, wait until the engine has cooled, then wrap a thick cloth around the pressure relief cap and turn it slowly. Step back while the pressure is released from the cooling system. When you are sure all the pressure has been released, turn and remove the pressure relief cap (still with a cloth). Inspect the engine coolant in the degas bottle for signs of engine oil. Is oil evident in the coolant? Yes : If engine oil is evident, GO to «ENGINE SYSTEM-GENERAL INFORMATION»(ref-233705) . No : GO to A4 .
4. A4 CHECK THE ENGINE FOR COOLANT Remove the oil level dipsticks from the engine. Is coolant evident in the oil? Yes : If coolant is in the engine, GO to «ENGINE SYSTEM-GENERAL INFORMATION»(ref-233705) . No : GO to A5 .
5. A5 CHECK THE ENGINE COOLANT FOR TRANSMISSION FLUID WARNING: Never remove the pressure relief cap while the engine is operating or when the cooling system is hot. Failure to follow these instructions can result in damage to the cooling system or engine or personal injury. To avoid having scalding hot coolant or steam blow out of the degas bottle when removing the pressure relief cap, wait until the engine has cooled, then wrap a thick cloth around the pressure relief cap and turn it slowly. Step back while the pressure is released from the cooling system. When you are sure all the pressure has been released, turn and remove the pressure relief cap (still with a cloth). Inspect the engine coolant in the degas bottle for signs of transmission fluid. Is transmission fluid evident in the coolant? Yes : INSTALL a new radiator. No : GO to A6 .
6. A6 PRESSURE TEST THE ENGINE COOLING SYSTEM Pressure test the engine cooling system. Refer to the «COMPONENT TESTS»(ref-233700-S39988562332006052600000) . Does the engine cooling system leak? Yes : REPAIR or INSTALL new components. TEST the system for normal operation. No : The cooling system is operational. GO to «SYMPTOM CHART»(ref-233700-S27364983742006052600000) .

PINPOINT TEST B: THE ENGINE OVERHEATS

1. B1 CHECK THE ENGINE COOLANT LEVEL NOTE: If the engine is hot, allow the engine to cool before proceeding. Key in OFF position. WARNING: Never remove the pressure relief cap while the engine is operating or when the cooling system is hot. Failure to follow these instructions can result in damage to the cooling system or engine or personal injury. To avoid having scalding hot coolant or steam blow out of the degas bottle when removing the pressure relief cap, wait until the engine has cooled, then wrap a thick cloth around the pressure relief cap and turn it slowly. Step back while the pressure is released from the cooling system. When you are sure all the pressure has been released, turn and remove the pressure relief cap (still with a cloth). Check the engine coolant level at the degas bottle. Is the engine coolant OK? Yes : GO to B2 . No : REFILL the engine coolant at the degas bottle. GO to «PINPOINT TEST A»(ref-233700-S16158233742006052600000) .
2. B2 CHECK THE COOLANT CONDITION Check the coolant for dirt, rust or contamination. Is the coolant condition OK? Yes : GO to B3 . No : FLUSH the engine cooling system. REFER to «COOLING SYSTEM DRAINING, FILLING AND BLEEDING»(ref-233700-S21960513852006052600000) . TEST the system for normal operation.
3. B3 CHECK FOR AN AIRFLOW OBSTRUCTION Inspect the A/C condenser core and radiator for obstructions such as leaves or dirt. Is there an obstruction? Yes : REMOVE the obstruction. CLEAN the A/C condenser core and radiator. TEST the system for normal operation. No : GO to B4 .
4. B4 CHECK THE THERMOSTAT OPERATION Key in START position. Start the engine and allow the engine to run for 10 minutes. Key in OFF position. Feel the upper and lower radiator hose. Are the upper and lower radiator hoses cold? Yes : CARRY OUT thermostat component tests. No : GO to B5 .
5. B5 CHECK THE COOLING FAN OPERATION Using the diagnostic tool, cycle the cooling fans to the HIGH and LOW positions. Do the cooling fans operate? Yes : REFER to «ENGINE SYSTEM-GENERAL INFORMATION»(ref-233705) for diagnosis and testing of the engine. No : GO to «PINPOINT TEST E»(ref-233700-S09783261922006052600000) to diagnose cooling fans.

PINPOINT TEST C: THE ENGINE DOES NOT REACH NORMAL OPERATING TEMPERATURE

1. C1 CHECK THE ENGINE TEMPERATURE Key in START position. Start the engine and allow the engine to idle for 10 minutes. Key in OFF position. Feel the upper and lower radiator hoses. Are the upper and lower radiator hoses cold? Yes : CARRY OUT thermostat component tests. No : REFER to «INSTRUMENT CLUSTER»(ref-233717) for diagnosis and testing of the engine coolant temperature gauge.

Scheme 1

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Scheme 6

Scheme 7

Scheme 8

1. D1 CHECK THE FAN CONTROL FAULT PIDS TO VERIFY FAN CONTROL PRIMARY CIRCUITS Key in ON position. Verify A/C is OFF, and engine temperature is below the temperature where the cooling fan would come on. Access the LFCF, MFCF and HFCF PIDs. Does the LFCF, MFCF and HFCF PID indicate a fault (or YES)? Yes : See «INTRODUCTION - GASOLINE»(ref-229953) to diagnose the cooling fan system. No : GO to D2 .
2. D2 CHECK THE OPERATION OF THE COOLING FANS (LOW/HIGH SPEED) Using the diagnostic tool, command the cooling fans on HIGH and LOW. Do the cooling fans operate? Yes : GO to D3 . No : If the driver and passenger side cooling fans do not operate at any speed, GO to D4 . If the driver/passenger side cooling fans do not operate at LOW speed, GO to D8 . If the driver side cooling fan does not operate at HIGH speed, GO to D8 . If the passenger side cooling fan does not operate at HIGH speed, GO to D12 .
3. D3 CHECK THE OPERATION OF THE COOLING FANS (MEDIUM SPEED) Key in OFF position. Disconnect: Fan Braking Relay C1028. Disconnect: Resistor Relay C1055. Key in ON position. Using a fused jumper, jumper between fan braking relay C1028 pin 5, circuit 228 (DB) and resistor relay C1055 pin 4, circuit 229 (RD/OG) harness side. Do the cooling fans operate? Yes : System OK. GO to «SYMPTOM CHART»(ref-233700-S27364983742006052600000) for further diagnosis. No : GO to D15 .
4. D4 CHECK THE FAN BRAKING RELAY Key in OFF position. Disconnect: Fan Braking Relay C1028. Carry out the Fan Braking Relay component test. Refer to «COMPONENT TESTING»(ref-233803) for component testing. Did the fan braking relay pass the component test? Yes : GO to D5 . No : INSTALL a new fan braking relay. TEST the system for normal operation.
5. D5 CHECK THE VOLTAGE TO THE FAN BRAKING RELAY Key in ON position. Measure the voltage between fan braking relay C1028 pin 87, circuit 228 (DB) harness side and ground. Is the voltage greater than 10 volts? Yes : GO to D6 . No : REPAIR the supply circuit. TEST the system for normal operation.
6. D6 CHECK THE RESISTOR RELAY Key in OFF position. Disconnect: Resistor Relay C1055. Carry out the Resistor Relay component test. Refer to «COMPONENT TESTING»(ref-233803) for component testing. Did the resistor relay pass the component test? Yes : GO to D7 . No : INSTALL a new resistor relay. TEST the system for normal operation.
7. D7 CHECK THE VOLTAGE TO THE RESISTOR RELAY Key in ON position. Connect: Fan Braking Relay C1028. Enter the following diagnostic mode on the diagnostic tool: Cycle the Cooling Fans to the HIGH Position. Measure the voltage between resistor relay C1055 pin 30, circuit 3850 (LG/VT) harness side and ground. Is the voltage greater than 10 volts? Yes : CONNECT the resistor relay C1055. GO to D8 . No : REPAIR the circuit. TEST the system for normal operation.
8. D8 CHECK THE VOLTAGE TO THE DRIVER SIDE COOLING FAN Key in ON position. Disconnect: Driver Side Cooling Fan Motor C1077. Enter the following diagnostic mode on the diagnostic tool: Cycle the Cooling Fans to the HIGH Position. Measure the voltage between driver side cooling fan motor C1077, circuit 229 (RD/OG) harness side and ground. Is the voltage greater than 10 volts? Yes : GO to D9 . No : REPAIR the circuit. TEST the system for normal operation.
9. D9 CHECK THE DRIVER SIDE COOLING FAN Connect a fused (40A) jumper wire between the positive battery post and driver side cooling fan motor C1077, circuit 229 (RD/OG) pin 3, component side and connect a fused (40A) jumper wire between the negative battery post and driver side cooling fan motor C1077 pin 1, circuit 57 (BK) component side. Does the driver side cooling fan operate? Yes : GO to D10 . No : INSTALL a new cooling fan motor. TEST the system for normal operation.
10. D10 CHECK THE HEDF RELAY Key in OFF position. Disconnect: HEDF Relay. Carry out the HEDF Relay component test. Refer to «COMPONENT TESTING»(ref-233803) for component testing. Did the HEDF relay pass the component test? Yes : GO to D11 . No : INSTALL a new HEDF relay. TEST the system for normal operation.
11. D11 CHECK CIRCUIT 57 (BK) Connect: HEDF Relay. Measure the resistance between driver side cooling fan motor C1077 pin 1, circuit 57 (BK) harness side and ground. Is the resistance less than 5 ohms? Yes : GO to D12 . No : REPAIR the circuit. TEST the system for normal operation.
12. D12 CHECK THE VOLTAGE TO THE PASSENGER SIDE COOLING FAN Connect: Driver Side Cooling Fan C1077. Disconnect: Passenger Side Cooling Fan C1074. Key in ON position. Enter the following diagnostic mode on the diagnostic tool: Command the Cooling Fans on HIGH and LOW. Measure the voltage between the passenger side cooling fan C1074 pin 3, circuit 229 (RD/OG) harness side and ground. Is the voltage greater than 10 volts? Yes : If the voltage is greater than 10 volts when the cooling fans are commanded HIGH and LOW, GO to D14 . If the voltage is greater than 10 volts when the cooling fans are commanded LOW only, GO to D13 . If the voltage is greater than 10 volts when the cooling fans are commanded HIGH only, REPAIR circuit 229 (RD/OG). TEST system for normal operation. No : REPAIR the circuit. TEST the system for normal operation.
13. D13 CHECK THE EDF RELAY Disconnect: EDF Relay. Carry out the EDF Relay component test. Refer to «COMPONENT TESTING»(ref-233803) for component testing. Did the EDF relay pass the component test? Yes : REPAIR circuit 229 (RD/OG). TEST the system for normal operation. No : INSTALL a new EDF relay. TEST the system for normal operation.
14. D14 CHECK THE PASSENGER SIDE COOLING FAN GROUND Measure the resistance between passenger side cooling fan C1074, circuit 57 (BK) harness side and ground. Is the resistance less than 5 ohms? Yes : INSTALL a new passenger side cooling fan. TEST the system for normal operation. No : REPAIR the circuit. TEST the system for normal operation.
15. D15 CHECK THE VOLTAGE TO THE RESISTOR Disconnect: Resistor C1027. Measure the voltage between resistor C1027 pin 1, circuit 228 (DB) harness side and ground. Is the voltage greater than 10 volts? Yes : GO to D16 . No : REPAIR the circuit. TEST the system for normal operation.
16. D16 CHECK CIRCUIT 229 (RD/OG) FOR AN OPEN Disconnect: Driver Side Cooling Fan Motor C1077. Measure the resistance between resistor C1027 pin 2, circuit 229 (RD/OG) and driver side cooling fan motor C1077 circuit 229 (RD/OG) harness side. Is the resistance less than 5 ohms? Yes : INSTALL a new resistor. TEST the system for normal operation. No : REPAIR the circuit. TEST the system for normal operation.

Scheme 9

Scheme 10

1. E1 CHECK THE A/C DUAL FUNCTION PRESSURE SWITCH INPUT TO THE PCM Key in START position. Verify the A/C is OFF. Monitor the A/C dual function pressure switch ACP PID. Does the A/C dual function pressure switch ACP PID read CLOSED? Yes : GO to E2 . No : GO to E4 .
2. E2 CHECK THE A/C HIGH PRESSURE SWITCH Disconnect: A/C Dual Function Pressure Switch C1062. Monitor A/C dual function pressure switch C1062 ACP PID. Does the A/C dual function pressure switch ACP PID read CLOSED? Yes : GO to E3 . No : If the A/C system is working correctly, INSTALL a new A/C high pressure switch. If the A/C system is not working correctly, REFER to «CLIMATE CONTROL SYSTEM-GENERAL INFORMATION»(ref-233738) to diagnose the A/C system.
3. E3 CHECK CIRCUIT 347 (BK/YE) FOR A SHORT TO GROUND Key in OFF position. Disconnect: PCM C175. Measure the resistance between PCM C175 pin 86, circuit 347 (BK/YE) harness side and ground. Is the resistance greater than 10,000 ohms? Yes : INSTALL a new PCM. See «INTRODUCTION - GASOLINE»(ref-229953) . No : REPAIR the circuit. TEST the system for normal operation.
4. E4 CHECK THE FAN BRAKING RELAY Disconnect: Fan Braking Relay. Did the cooling fans stop? Yes : INSTALL a new fan braking relay. TEST the system for normal operation. No : GO to E5 .
5. E5 CHECK CIRCUIT 386 (LB) FOR A SHORT TO GROUND Key in OFF position. Disconnect: PCM C175. Measure the resistance between PCM C175 pin 28, circuit 386 (LB) harness side and ground. Is the resistance greater than 10,000 ohms? Yes : GO to E6 . No : REPAIR circuit 386 (LB). TEST the system for normal operation.
6. E6 CHECK CIRCUITS 3850 (LG/VT) AND 229 (RD/OG) FOR A SHORT TO POWER Disconnect: Resistor Relay. Did the cooling fans stop? Yes : REPAIR circuit 3850 (LG/VT). TEST the system for normal operation. No : REPAIR circuit 229 (RD/OG). TEST the system for normal operation.

Pressure Test

1. Turn the engine OFF.
2. Check the engine coolant level. Refer to «COOLING SYSTEM DRAINING, FILLING AND BLEEDING»(ref-233700-S21960513852006052600000) .
3. Connect the Radiator/Heater Core Pressure Tester to the degas bottle nipple and overflow hose. Install a pressure test pump to the quick-connect fitting of the test adapter.
4. Slowly depress the plunger of the pressure test pump until the pressure gauge reading stops increasing and note the highest pressure reading obtained.
5. If the pressure relief cap does not hold pressure, remove and wash the pressure relief cap in clean water to dislodge all foreign particles from the gaskets. Check the sealing surface in the filler neck.
6. Pressure check the pressure relief cap. If 8-9 kPa (13 psi) cannot be reached or if more than 12 kPa (18 psi) show on the gauge, install a new pressure relief cap.
7. Pressurize the engine cooling system as described in Step 4 (using a pressure relief cap that operates within the specified upper and lower pressure limits). Observe the gauge reading for approximately two minutes; refer to «GENERAL SPECIFICATIONS»(ref-233700-S15783534612006052600000) . Pressure should not drop during this time.
8. Release the system pressure by loosening the pressure relief cap. Check the engine coolant level and replenish, if necessary, with the correct engine coolant mixture. Refer to «COOLING SYSTEM DRAINING, FILLING AND BLEEDING»(ref-233700-S21960513852006052600000) .

Radiator Leak Test, Removed From the Vehicle

Note. Always install plugs in the transmission fluid cooler fittings before leak testing or cleaning any radiator.

Note. Clean the radiator before leak testing to avoid contamination of tank.

1. Leak-test the radiator in clean water with 138 kPa (20 psi) air pressure.