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Home >> Ford >> 2000 >> Contour SE, 2.5 L, Standard >> Repair and Diagnosis >> Engine Performance >> Testing & Diagnosis >> Engine Controls - Self-Diagnostics - EEC-V - CNG, Flex-Fuel & Gasoline >> System Tests >> Test KF: Fan Control Relay >> Diagnostic Aids

Diagnostic Aids

This system test is for Contour, Crown Victoria, Grand Marquis, Mystique, Sable, Taurus, Town Car and Windstar only. On all models, PCM determines engine cooling fan requirements and controls fan operation through Low Fan Control (LFC) and High Fan Control (HFC) circuits. HFC relay is normally open.

Perform this test only when instructed by QUICK TEST or directed by other test procedures. This test is only intended to diagnose:

Fig 1: Identifying LFC/HFC Circuits (Continental, Sable & Taurus)
G99F02676Courtesy of FORD MOTOR CO.
Fig 2: Identifying LFC/HFC Circuits (Contour, Cougar, Focus - With A/C, & Mystique)
G00013299Courtesy of FORD MOTOR CO.
Fig 3: Identifying LFC/HFC Circuits (Crown Victoria, Grand Marquis & Town Car)
G99C02670Courtesy of FORD MOTOR CO.
Fig 4: Identifying Cooling Fan Relay Circuits (Focus - Without A/C)
G00013300Courtesy of FORD MOTOR CO.
Fig 5: Identifying LFC/HFC Circuits (Windstar)
G00013301Courtesy of FORD MOTOR CO.

  1. 1) DTC P1474 & P1479: Check For VPWR To Applicable Fan Control Relay

    DTC P1474 indicates a Low Speed Fan Control (LFC) primary circuit failure. DTC P1479 indicates a High Speed Fan Control (HFC) primary circuit failure. Possible causes are.
    • Open Or Shorted LFC Or HFC Circuit
    • Open VPWR Circuit To Fan Control Relay
    • Faulty Fan Control Relay (LFC or HFC)
    • Faulty PCM

    Turn ignition switch to OFF position. Disconnect appropriate fan control relay. Turn ignition switch to ON position. Using a voltmeter, measure voltage between VPWR terminal at appropriate fan control relay harness connector and negative battery terminal. See Fig 1-Fig 5 . If voltage is more than 10.5 volts, go to next step. If voltage is 10.5 volts or less, repair open in VPWR circuit to appropriate fan control relay.

  2. 2) Check For LFC Or HFC Circuit Cycling

    Turn ignition switch to ON position. Using scan tool, access OUTPUT TEST MODE. See OUTPUT TEST MODE  in ADDITIONAL SYSTEM FUNCTIONS. Connect a test light between VPWR terminal and LFC or HFC terminal at appropriate fan control relay harness connector. Using scan tool, command appropriate cooling fan speed ON and OFF. If test light turns on and off, replace appropriate fan control relay. If test light does not turn on and off, repeat test step. If test light still does not turn on and off, turn ignition switch to OFF position, remove test light and go to next step.

  3. 3) Check LFC Or HFC Circuit For Short To Power In Harness

    Turn ignition switch to OFF position. Disconnect PCM connector(s). Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Turn ignition switch to ON position. Measure voltage between ground and LFC or HFC terminal at appropriate fan control relay harness connector. If voltage is less than one volt, go to next step. If voltage is one volt or more, repair LFC or HFC circuit for short to power.

  4. 4) Check LFC Or HFC Circuit For Short To Ground In Harness

    Turn ignition switch to OFF position. Disconnect scan tool from DLC. Measure resistance between ground and LFC or HFC terminal at appropriate fan control relay harness connector. If resistance is more than 10 k/ohms, go to next step. If resistance is 10 k/ohms or less, repair LFC or HFC circuit short to ground.

  5. 5) Check For Open LFC Or HFC Circuit

    Measure resistance between appropriate PCM connector terminal (LFC or HFC) and LFC or HFC terminal at appropriate fan control relay harness connector. If resistance is less than 5 ohms, replace PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. Program PCM. See FLASH VEHICLE IDENTIFICATION BLOCK PROCEDURE . If resistance 5 ohms or more, repair open in LFC or HFC circuit.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 5) to step 10). No test procedures have been omitted.

  6. 10) Continuous Memory DTC P1474: Check LFC Circuit For Open Or Short To PWR

    Continuous Memory DTC P1474 indicates a Low Speed Control Fan (LFC) circuit failure occurred during vehicle operation. Possible causes are:
    • Open LFC Relay VPWR Circuit
    • Open Or Shorted LFC Circuit

    Turn ignition switch to OFF position. Ensure A/C and defroster are off. Disconnect cooling fan motor connector (both fan motor connectors on models with 2 fans). Inspect connector(s) for loose, damaged or corroded terminals. Repair as necessary. Connect a test light between negative battery terminal and low cooling fan harness connector LOW FAN PWR terminal (either harness connector on models with 2 fans). Turn ignition switch to ON position. Using scan tool, access OUTPUT TEST MODE. See OUTPUT TEST MODE  in ADDITIONAL SYSTEM FUNCTIONS. Command low speed fan ON. Test light should illuminate. Observe test light for indication of fault (test light will turn off to indicate fault) while performing the following:

    • Shake and bend LFC circuit between PCM and LFC relay.
    • Shake and bend VPWR circuit to LFC relay.
    • Lightly tap on LFC relay to simulate road shock.

    If fault is indicated, turn ignition switch to OFF position. Isolate and repair open or short to power in wiring harness. If fault is not indicated, go to next step.

  7. 11) Check LFC Circuit For Short To Ground

    Turn ignition switch to ON position. Ensure cooling fan motor connector(s) are disconnected and test light is still connected. Using scan tool, command low speed fan OFF. Test light should be off. Observe test light for indication of fault (test light will turn on to indicate fault) while performing the following:
    • Shake and bend LFC circuit between PCM and LFC relay.
    • Lightly tap on LFC relay to simulate road shock.

    If fault is indicated, isolate and repair short to ground in wiring harness. If fault is not indicated, problem is intermittent. Go to TEST Z .

    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 11) to step 20). No test procedures have been omitted.

  8. 20) Continuous Memory DTC P1479: Check HFC Circuit For Open Or Short To PWR

    Continuous Memory DTC P1479 indicates a High Speed Fan Control (HFC) circuit failure has occurred during vehicle operation. Possible causes are:
    • Open HFC Relay VPWR Circuit
    • Open Or Shorted HFC Circuit

    Turn ignition switch to OFF position. Ensure A/C and defroster are off. Disconnect cooling fan motor connector (both fan motor connectors on models with 2 fans). Inspect connector(s) for loose, damaged or corroded terminals. Repair as necessary. Connect a test light between ground and HIGH FAN PWR terminal at fan motor harness connector (either connector on models with 2 fans). Turn ignition switch to ON position. Using scan tool, access OUTPUT TEST MODE. See OUTPUT TEST MODE  in ADDITIONAL SYSTEM FUNCTIONS. Command high speed fan ON. Test light should illuminate. Observe test light for indication of fault (test light will turn off to indicate fault) while performing the following:

    • Shake and bend HFC circuit between PCM and HFC relay.
    • Shake and bend VPWR circuit to HFC relay.
    • Lightly tap on HFC relay to simulate road shock.

    If fault is indicated, turn ignition switch to OFF position. Isolate and repair open or short to power in wiring harness. If fault is not indicated, go to next step.

  9. 21) Check HFC Circuit For Short To Ground

    Turn ignition switch to ON position. Ensure cooling fan motor connector(s) are disconnected and test light is still installed. Using scan tool, command high speed fan OFF. Test light should be off. Observe test light for indication of fault (test light will turn on to indicate fault) while performing the following:
    • Shake and bend HFC circuit between PCM and HFC relay.
    • Lightly tap on HFC fan control relay to simulate road shock.

    If fault is indicated, turn ignition switch to OFF position. Isolate and repair short to ground in wiring harness. If fault is not indicated, problem is intermittent. Go to TEST Z .

    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 21) to step 30). No test procedures have been omitted.

  10. 30) Electric Cooling Fan Problem (With No DTCs): Check Fan Operation

    Turn ignition switch to ON position. Using scan tool, access OUTPUT TEST MODE. See OUTPUT TEST MODE  in ADDITIONAL SYSTEM FUNCTIONS. Command cooling fan ON and check fan operation. On models with 2-speed fan, check both fan speeds. Wait 20 seconds after commanding high fan speed on. Verify fan changes speed. On all models, if fan(s) functions properly, turn ignition switch to OFF position. Return to test that directed you here. If fan(s) do not function properly, go to step  50) (Contour, Cougar, Focus with A/C, Mystique and Windstar), go to step  41) (Focus without A/C), or go to next step (all other models).

  11. 31) Determine Fan Operation

    During operational check of both fan speeds, if cooling fan(s) operated at one speed only, go to step  40). If cooling fan(s) did not operate at any speed, go to next step. On Sable and Taurus, if one cooling fan did not operate properly, but other fan operated properly, go to step  70).

  12. 32) Cooling Fan Will Not Operate At Any Speed: Command High Speed Fan ON & Check For Voltage To Cooling Fan

    Ensure ignition switch is in ON position, scan tool is still connected and in OUTPUT TEST MODE , and cooling fan is commanded off. Disconnect cooling fan motor connector (both fan motor connectors on Sable and Taurus). Using scan tool, command high speed cooling fan ON. Using a voltmeter, measure voltage between ground and HIGH FAN PWR terminal at fan motor harness connector (either connector on Sable and Taurus). If voltage is 10 volts or less, go to next step. If voltage is more than 10 volts, check cooling fan ground circuit, go to step  37).

  13. 33) Check B+ Circuit To HFC & LFC Relays

    Turn ignition switch to OFF position. Ensure cooling fan connector(s) are disconnected. Disconnect HFC and LFC relays. Using a DVOM, measure voltage between negative battery terminal and HFC and LFC relay harness connector B+ terminals. If both voltage measurements are more than 10 volts, go to next step. If either voltage measurement is 10 volts or less, check for open in B+ circuit. Check appropriate B+ circuit fuse(s). If fuse(s) is okay, check for open in B+ circuit. Repair as necessary. If fuse(s) is blown, check B+ circuit for short to ground before replacing fuse. Repair as necessary. Recheck cooling fan operation.
    14. NOTE: Contour, Cougar, Focus (with A/C), Mystique and Windstar have dropping resistors in-line to cooling fans. See Fig 2 and Fig 5 . For dropping resistor locations, see COOLING FAN RESISTOR LOCATIONS  table.

  14. 34) Check For Open In LOW FAN PWR & HIGH FAN PWR Circuits
    Using a DVOM, measure resistance of HIGH FAN PWR circuit between appropriate HFC relay harness connector terminal and appropriate cooling fan harness connector terminal. Using a DVOM, measure resistance of LOW FAN PWR circuit between appropriate LFC relay harness connector terminal and appropriate cooling fan harness connector terminal. If both resistance measurements are less than 5 ohms, go to next step. If either resistance measurement is 5 ohms or more, locate and repair open in affected circuit. Recheck cooling fan operation.
    COOLING FAN RESISTOR LOCATIONS

    Application Location
    Contour, Cougar & Mystique In Engine Compartment, Below Driver Side Cooling Fan
    Focus With A/C In Engine Compartment, In Wiring Harness Between Cooling Fans
    Windstar In Engine Compartment, Between Battery & Left Headlight

  15. 35) Command Low Speed Fan ON & Check For Voltage To Cooling Fans

    Reconnect HFC and LFC relays. Ensure cooling fan motor connector(s) are disconnected. Turn ignition switch to ON position. Using scan tool, access OUTPUT TEST MODE . Command low speed fan ON. Measure voltage between ground and LOW FAN PWR terminal at cooling fan motor harness connector (either connector on Sable and Taurus). If voltage is more than 10 volts, turn ignition switch to OFF position, replace HFC relay and go to step  37). If voltage is 10 volts or less, turn ignition switch to OFF position, go to step  75) and follow procedure for low speed fan inoperative. After repair, repeat step  75) and follow procedure for high speed fan inoperative.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 35) to step 37). No test procedures have been omitted.

  16. 37) Check Cooling Fan Ground Circuit

    Ensure ignition switch is in OFF position. Disconnect scan tool from DLC. Measure resistance of ground circuit between chassis ground and ground terminal at cooling fan motor harness connector. If resistance is less than 5 ohms, replace cooling fan motor(s). If resistance is 5 ohms or more, locate and repair open in ground circuit. Recheck cooling fan operation.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 37) to step 40). No test procedures have been omitted.

  17. 40) Determine Which Fan Speed Is Operational

    If high speed fan was inoperative in step  31), go to step  46). If low speed fan was inoperative in step  31), go to next step.

  18. 41) Low Speed Fan Inoperative: Command Low Fan ON & Check Voltage To Cooling Fan

    Turn ignition switch to ON position. Ensure scan tool is still in OUTPUT TEST MODE  with fan commanded off. Disconnect cooling fan motor connector (both connectors on Sable and Taurus). Using scan tool, command low speed fan ON. Measure voltage between ground and LOW FAN PWR terminal at cooling fan motor harness connector (either connector on Sable and Taurus). If voltage is more than 10 volts, check ground circuit to cooling fan motor. If ground circuit is okay, replace fan motor and recheck cooling fan operation. If voltage is 10 volts or less, go to next step.

  19. 42) Check B+ Voltage To LFC Relay

    Disconnect LFC relay. Using a DVOM, measure voltage between negative battery terminal and LFC relay harness connector B+ terminal. If voltage is more than 10.5 volts, go to next step. If voltage is 10.5 volts or less, check for open in B+ circuit. Check appropriate B+ circuit fuse(s). If fuse(s) is okay, check for open in B+ circuit. Repair as necessary. If fuse(s) is blown, check B+ circuit for short to ground before replacing fuse. Repair as necessary. Recheck cooling fan operation.

  20. 43) Check For Open In Low Fan PWR Circuit

    Using a DVOM, measure resistance of LOW FAN PWR circuit between LFC relay harness connector and appropriate cooling fan harness connector(s). If resistance is less than 5 ohms, go to next step. If resistance measurement is 5 ohms or more, locate and repair open circuit. Check in-line fan dropping resistor if equipped. See COOLING FAN RESISTOR LOCATIONS  table. Repair dropping resistor or open in affected circuit. Recheck cooling fan operation.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 43) to step 46). No test procedures have been omitted.

  21. 46) High Speed Fan Inoperative: Command High Speed Fan ON & Check For Voltage To Cooling Fan

    Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC) if not previously connected. Turn ignition switch to ON position. Using scan tool, access OUTPUT TEST MODE  and command cooling fan OFF. Disconnect appropriate cooling fan connector (both connectors on models with 2 fans). Command high speed fan ON. Using a DVOM, measure voltage between negative battery terminal and cooling fan harness connector HIGH FAN PWR terminal (appropriate connector on models with 2 fans). If voltage is 10 volts or less, turn ignition switch to OFF position and go to next step. If voltage is more than 10 volts, check ground circuit to cooling fan. If ground circuit is okay, replace cooling fan motor and recheck cooling fan operation.

  22. 47) Check B+ Voltage To HFC Relay

    Disconnect HFC relay. Using a DVOM, measure voltage between negative battery terminal and HFC relay harness connector B+ terminal. If voltage is more than 10.5 volts, go to next step. If voltage is 10.5 volts or less, check for open in B+ circuit. Check appropriate B+ circuit fuse(s). If fuse(s) is okay, check for open in B+ circuit. Repair as necessary. If fuse(s) is blown, check B+ circuit for short to ground before replacing fuse. Repair as necessary. Recheck cooling fan operation.

  23. 48) Check For Open High Fan PWR Circuit

    Turn ignition switch to OFF position. Using a DVOM, measure resistance of HIGH FAN PWR circuit between HFC relay harness connector and appropriate cooling fan harness connector. If resistance is less than 5 ohms, go to step  75). If resistance is 5 ohms or more, repair open in HIGH FAN PWR circuit. Recheck cooling fan operation.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 48) to step 50). No test procedures have been omitted.

  24. 50) Low &/Or High Speed Cooling Fan Inoperative (Contour, Cougar, Focus With A/C, Mystique & Windstar): Check For B+ Voltage To HFC & LFC Relays

    If one cooling fan is inoperative, but other cooling fan operates normally, go to step  70). Turn ignition switch to OFF position. Disconnect LFC and HFC relays. Measure voltage between ground and B+ terminal at both LFC and HFC relay harness connectors. If both voltage readings are more than 10.5 volts, go to next step. If any voltage reading is 10.5 volts or less, locate and repair open in B+ circuit. If fuse or fuse link was blown, check and repair cause of blown fuse or fuse link. Recheck cooling fan operation.

  25. 51) Check For Open Fan PWR Circuit, Fan Ground & Internal Fan Circuits

    Ensure ignition switch is turned to OFF position. Using a DVOM, measure resistance between negative battery terminal and both LFC and HFC relay harness connector FAN PWR terminals. If both resistance measurements are less than 15 ohms, go to next step. If either resistance measurement is 15 ohms or more, go to step  56).

  26. 52) Check FAN PWR Circuit For Short To Ground

    Disconnect both cooling fan harness connectors. Using a DVOM, measure resistance between negative battery terminal and HFC relay harness connector FAN PWR terminal. If resistance is more than 10 k/ohms, go to next step. If resistance is 10 k/ohms or less, locate and repair short to ground in FAN PWR circuit. Recheck cooling fan operation.

  27. 53) Check HFC & LFC Relay Operation

    Ensure cooling fan motor connectors are disconnected. Reconnect HFC and LFC relays. Using scan tool, access OUTPUT TEST MODE. See OUTPUT TEST MODE  under ADDITIONAL SYSTEM FUNCTIONS. Perform appropriate following test procedure as follows:

    • HFC Relay

      Using scan tool, command high speed fan ON. Wait 15 seconds. Using a DVOM, measure voltage between negative battery terminal and cooling fan harness connector FAN PWR terminal (either connector). Voltage should be more than 10.5 volts.

    • LFC Relay

      Using scan tool, command low speed fan ON. Using a DVOM, measure voltage between negative battery terminal and cooling fan harness connector FAN PWR terminal (either connector). Voltage should be more than 10 volts.

    If both voltage readings are as specified, replace cooling fan motor(s). If any voltage reading is not as specified, note which fan speed is inoperative and go to step  75).

    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 53) to step 56). No test procedures have been omitted.

  28. 56) Check For Open FAN PWR Circuit Between Cooling Fan, & HFC & LFC Relays

    Turn ignition switch to OFF position. Disconnect cooling fan connector (either connector). Using a DVOM, measure resistance of FAN PWR circuit between cooling fan harness connector and both HFC and LFC relay harness connectors. If both resistance measurements are less than 15 ohms, go to next step. If either resistance measurement is 15 ohms or more, locate and repair open in FAN PWR circuit. If open is only between LFC relay and cooling fan, check in-line fan dropping resistor. See COOLING FAN RESISTOR LOCATIONS  table. Recheck cooling fan operation.

  29. 57) Check Cooling Fan Ground Circuit

    Measure resistance between ground and ground terminal at cooling fan motor harness connector. If resistance is less than 5 ohms, replace inoperative cooling fan motor(s). If resistance is 5 ohms or more, locate and repair open in ground circuit. Recheck cooling fan operation.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 57) to step 60). No test procedures have been omitted.
    30. NOTE: Perform test step  60) when directed from ELECTRIC COOLING FAN ALWAYS ON symptom under SYMPTOMS in TROUBLE SHOOTING - NO CODES - EEC-V (GASOLINE) article.

  30. 60) Low &/Or High Speed Cooling Fan Always Runs (No DTCs): Verify Fan Is Not On Because Of A/C High Pressure Switch Input To PCM
    Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Start engine. Using scan tool, select ACP PID from PID/DATA MONITOR & RECORD menu. If ACP PID value indicates OPEN, input is okay. Go to step  65). If ACP PID indicates CLOSED, Powertrain Control Module (PCM) will turn cooling fan on when A/C high pressure switch is "closed". Leave engine running and go to next step.

  31. 61) Check A/C High Pressure Switch (Normally Open Contacts)

    Disconnect A/C high pressure switch. Using scan tool, select ACP PID from PID/DATA MONITOR & RECORD menu. If ACP PID indicates CLOSED, turn ignition switch to OFF position and go to next step to check A/C high pressure switch input to PCM. If ACP PID indicates OPEN, turn ignition switch to OFF position and reconnect A/C high pressure switch. Check A/C high pressure switch and A/C system for proper operation. Service A/C system as necessary. See appropriate article in AIR CONDITIONING & HEATING.

  32. 62) Check ACPSW Circuit For Short To Ground In Harness

    Disconnect scan tool from DLC. Disconnect PCM connector. Using a DVOM, measure resistance between PCM harness connector terminal No. 86 and chassis ground. See Figure. If resistance is more than 10 k/ohms, replace PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. Program PCM. See FLASH VEHICLE IDENTIFICATION BLOCK PROCEDURE . If resistance is 10 k/ohms or less, repair short to ground in ACPSW circuit.
    33. NOTE: Perform test step  63) when directed from ELECTRIC COOLING FAN ALWAYS ON symptom under SYMPTOMS in TROUBLE SHOOTING - NO CODES - EEC-V (GASOLINE) article.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 63) to step 65). No test procedures have been omitted.

  33. 63) Low &/Or High Speed Cooling Fan Always Runs (No DTCs): Ensure Fan Is Not On Because Of A/C High Pressure Sensor Input To PCM
    Turn ignition switch to OFF position. Turn A/C off. Connect scan tool to Data Link Connector (DLC). Start engine. Using scan tool, access PID/DATA MONITOR & RECORD menu. See PARAMETER IDENTIFICATION MODE  under ADDITIONAL SYSTEM FUNCTIONS. Select ACP V PID from PID/DATA MONITOR & RECORD menu. If ACP V PID voltage reading is 3 volts or less, input is not causing cooling fan to operate, go to step  65). If ACP V PID voltage reading is more than 3 volts, turn ignition switch to OFF position. Check A/C system for high system pressure. Service A/C system as necessary. See appropriate article in AIR CONDITIONING & HEATING.

  34. 65) Check LFC Relay Always Closed

    Ensure A/C and defroster are off. Turn ignition switch to OFF position. Disconnect LFC relay. Turn ignition switch to ON position, engine off. Check cooling fan operation. If cooling fan stops, go to step  80). If cooling fan continues to run on Focus without A/C, repair short to VPWR in FAN PWR circuit. If cooling fan continues to run on all other models, go to next step.

  35. 66) Check HFC Relay

    Turn ignition switch to OFF position. Disconnect HFC and LFC relays. Turn ignition switch to ON position. Check cooling fan operation. If cooling fan stops, go to step  80). If cooling fan remains on, perform appropriate following test procedure as follows:

    • Cougar, Focus, Sable, Taurus, Ranger & Windstar

      Turn ignition switch to OFF position. Repair short to VPWR in FAN PWR circuit. Recheck cooling fan operation.

    • Continental, Crown Victoria, Grand Marquis & Town Car

      Go to next step.

  36. 67) Check Low Fan PWR Circuit For Short To Power In Harness

    Turn ignition switch to OFF position. Disconnect cooling fan connector(s). Turn ignition switch to ON position. Using a DVOM, measure voltage between negative battery terminal and cooling fan harness connector LOW FAN PWR terminal. If voltage is less than one volt, repair short to VPWR in HIGH FAN PWR circuit. Recheck cooling fan operation. If voltage is one volt or more, repair short to VPWR in LOW FAN PWR circuit. Recheck cooling fan operation.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 67) to step 70). No test procedures have been omitted.

  37. 70) One Cooling Fan Inoperative & Other Cooling Fan Operates Normal (No DTCs): Check For Open In Ground Circuit To Inoperative Cooling Fan

    Turn ignition switch to OFF position. Disconnect inoperative cooling fan motor connector. Measure resistance between chassis ground and cooling fan motor harness connector ground terminal. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in ground circuit. Recheck cooling fan operation.

  38. 71) Command Cooling Fan ON & Check For Voltage To Fan

    Disconnect remaining cooling fan motor. Using scan tool, access OUTPUT TEST MODE. See OUTPUT TEST MODE  in ADDITIONAL SYSTEM FUNCTIONS. Command high speed fan ON. Measure voltage between ground and HIGH FAN PWR terminal at inoperative cooling fan motor harness connector. On Sable and Taurus, also command low speed fan ON. Measure voltage between ground and LOW FAN PWR terminal at inoperative cooling fan motor harness connector. On all models, if voltage is more than 10 volts (at both HIGH and LOW FAN PWR terminals on Sable and Taurus), replace inoperative cooling fan motor. Recheck cooling fan operation. If voltage is 10 volts or less, locate and repair open in HIGH FAN PWR circuit (HIGH or LOW FAN PWR circuit on Sable and Taurus) between inoperative cooling fan motor and splice to other fan motor. Recheck fan operation.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 71) to step 75). No test procedures have been omitted.

  39. 75) Attempt To Access Parameter Identifications With Scan Tool

    An inoperative low, medium or high speed cooling fan can be caused by a primary circuit fault, even though a DTC was not set. Check if scan tool being used is capable of accessing PID values while in OUTPUT TEST MODE. See OUTPUT TEST MODE  under ADDITIONAL SYSTEM FUNCTIONS. If PID access is possible, check primary circuits, go to next step. If PID access is not possible and low speed fan is inoperative or cooling fan is inoperative for one speed cooling fans, go to step  78). If PID access is not possible and high speed fan is inoperative, go to step  79).

  40. 76) Check Operation Of Low, Medium &/Or High Speed Fan Primary Circuits

    Reconnect all cooling fan and relay connectors. Turn ignition switch to ON position. Using scan tool, access OUTPUT TEST MODE. Perform appropriate test procedure as follows:

    • Low Speed Fan Inoperative (Cooling Fan Inoperative For One Speed Cooling Fans)

      Using scan tool, select LFC and LFCF PIDs. With low speed fan commanded OFF by PCM, LFC PID should read OFF and LFCF PID should read NO. Command low speed fan ON. LFC PID should now read ON and LFCF PID should still read NO.

    • High Speed Fan Inoperative

      Using scan tool, select HFC and HFCF PIDs. With high speed fan commanded OFF by PCM, HFC PID should read OFF and HFCF PID should read NO. Command high speed fan ON. HFC PID should read ON and HFCF PID should still read NO.

    If LFCF and HFCF PIDs indicated YES with fan commanded ON or OFF, an LFC or HFC primary circuit fault is detected. Go to step  1) and perform appropriate diagnosis for DTC P1474 (if LFCF PID value was YES), or DTC P1479 (if HFCF PID value was YES). If LFCF or HFCF PIDs indicated NO with fan commanded ON and OFF, LFC and HFC primary circuits are okay. Replace appropriate LFC relay (if low speed fan is inoperative) or HFC relay (if high speed fan is inoperative). Ensure applicable FAN PWR circuit is not shorted to ground. Recheck cooling fan operation.

    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 76) to step 78). No test procedures have been omitted.

  41. 78) Check Operation Of Low Speed Fan Primary Circuits

    Reconnect all connectors. Turn ignition switch to ON position. Connect a test light between VPWR terminal and LFC terminal at LFC relay harness connector. Using scan tool, access OUTPUT TEST MODE. See OUTPUT TEST MODE  in ADDITIONAL SYSTEM FUNCTIONS. While observing scan tool, command low speed fan ON then OFF. If test light turns on then off, primary circuits are okay. Replace LFC relay. Verify appropriate FAN PWR circuit is not shorted to ground. Recheck cooling fan operation. If test light did not turn on then off, an LFC primary circuit fault is detected. Go to step  1) and perform diagnosis for DTC P1474.

  42. 79) Check Operation Of High Speed Fan Primary Circuits

    Reconnect all connectors. Turn ignition switch to ON position. Connect a test light between VPWR terminal and HFC terminal at HFC relay harness connector. Using scan tool, access OUTPUT TEST MODE. See OUTPUT TEST MODE  in ADDITIONAL SYSTEM FUNCTIONS. While observing scan tool, command high speed fan ON then OFF. If test light turns on then off, primary circuits are okay. Replace HFC relay. Verify appropriate FAN PWR circuit is not shorted to ground. Recheck cooling fan operation. If test light did not turn on then off, HFC primary circuit fault is detected. Go to step  1) and perform diagnosis for DTC P1479.

  43. 80) Check Operation Of Low Or High Speed Fan Primary Circuits

    An inoperative high speed or low speed fan can be caused by a primary circuit fault, even though a DTC was not set. Reconnect all cooling fan and relay connectors. Turn ignition switch to ON position. Using scan tool, access OUTPUT TEST MODE. See OUTPUT TEST MODE  in ADDITIONAL SYSTEM FUNCTIONS. Perform appropriate test procedure as follows:

    • Fan Stops Running With LFC Relay Disconnected

      Using scan tool, select LFC and LFCF PIDs from PID/DATA MONITOR & RECORD menu. Command low speed fan OFF. LFC PID should read OFF and LFCF PID should read NO.

    • Fan Stops Running With HFC Relay Disconnected

      Using scan tool, select HFC and HFCF PIDs from PID/DATA MONITOR & RECORD menu. Command high speed fan OFF. HFC PID should read OFF and HFCF PID should read NO.

    If LFCF or HFCF PIDs indicated YES with fan commanded OFF, an LFC or HFC primary circuit fault is detected. Go to step  1) and perform appropriate diagnosis for DTC P1474 (if LFCF PID was YES), or DTC P1479 (if HFCF PID was YES). If LFCF or HFCF PIDs indicated NO with fan commanded OFF, LFC and HFC primary circuits are okay. Replace LFC relay (if fan stopped running with LFC relay disconnected), or HFC relay (if fan stopped running with HFC relay disconnected). Recheck cooling fan operation.

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