Start by checking/replacing the relays !
60) Low And/Or High Speed Cooling Fan Always Runs (No DTCs): Verify Fan Is Not On Because Of A/C High Pressure Switch Input To PCM (If Equipped)
Start engine. Using scan tool, select ACP PID from PID/DATA monitor menu. If PID value indicates CLOSED, leave engine running and go to next step. If PID value indicates OPEN, go to step 65).
61) Check A/C High Pressure Switch (If Equipped)
Disconnect A/C high pressure switch. Again, check ACP PID value. If PID value indicates CLOSED, turn ignition off and go to next step. If PID value indicates OPEN, turn ignition off and reconnect A/C high pressure switch. Service A/C system as necessary.
62) Check For Short To Ground In ACPSW Circuit
Disconnect scan tool from DLC. Disconnect PCM connector. Measure resistance between PCM connector pin No. 86 and ground. If resistance is more than 10,000 ohms, replace PCM. If resistance is 10,000 ohms or less, repair short to ground in ACPSW circuit.
63) Low And/Or High Speed Cooling Fan Always Runs (No DTCs): Verify Fan Is Not On Because Of A/C High Pressure Sensor Input To PCM (If Equipped)
Turn A/C off. Start engine. Using scan tool, select ACP V PID from PID/DATA monitor menu. If PID voltage indicates more than 3 volts, turn ignition off. Service A/C system as necessary. If PID voltage is 3 volts or less, go to next step.
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.
65) Low And/Or High Speed Cooling Fan Always Runs
Turn A/C (if equipped) and defroster off. Turn ignition off. Disconnect LFC relay. Turn ignition on. If cooling fan continues to run, go to next step. If cooling fan stops, go to step 80).
66) Check HFC Relay
Turn ignition off. Disconnect HFC and LFC relays. Turn ignition on. Check cooling fan operation. If cooling fan stops, go to step 80). If cooling fan remains on, turn ignition off. On Contour, Cougar, Mystique and Windstar, repair FAN PWR circuit for short to power. Recheck cooling fan operation. On all other models, go to next step.
67) Check Low Fan PWR Circuit For Short To Power
Turn ignition off. Disconnect cooling fan motor connector (both fan motor connectors on Sable and Taurus). Turn ignition on. Measure voltage between ground and LOW FAN PWR terminal at cooling fan motor connector. If voltage is less than one volt, repair HIGH FAN PWR circuit for short to power. Recheck cooling fan operation. If voltage is one volt or more, repair LOW FAN PWR circuit for short to power. Recheck 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.
70) One Cooling Fan Inoperative & Other Cooling Fan Operates Normally (No DTCs)
Turn ignition off. Disconnect inoperative cooling fan motor connector. Measure resistance between ground and ground terminal at fan motor connector. 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.
71) Check For Voltage To Fan
Disconnect remaining cooling fan motor. Using scan tool, access OUTPUT TEST MODE. See OUTPUT TEST MODE under SELF-DIAGNOSTICS. Command high speed fan ON. Measure voltage between ground and HIGH FAN PWR terminal at inoperative cooling fan motor 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 connector. On all models, if voltage is more than 10 volts (at both 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 circuit 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.
75) Accessing Parameter Identification (PID)
An inoperative high speed or low speed 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. If PID access is possible, go to next step. If PID access is not possible, go to step 78) if low speed fan is inoperative or step 79) if high speed fan is inoperative.
76) Check Operation Of Primary Fan Circuits
Reconnect all connectors. Turn ignition on. Using scan tool, access OUTPUT TEST MODE. See OUTPUT TEST MODE under SELF-DIAGNOSTICS. Perform the appropriate test procedure as follows:
Low Speed Fan Inoperative
Using scan tool, select LFCA and LFCF PIDs from PID/DATA monitor menu. With low speed fan off, LFCA PID should read OFF and LFCF PID should read NO. Command low speed fan ON. LFCA PID should read ON and LFCF PID should still be NO.
High Speed Fan Inoperative
Using scan tool, select HFCA and HFCF PIDs from PID/DATA monitor menu. Command high speed fan ON. HFCA PID should read OFF and LFCF PID should read NO. Command high speed fan ON. HFCA PID should read ON and HFCF PID should still be NO.
If LFCF PID or HFCF PID indicated YES with fan commanded on or off, a primary circuit fault is detected. Go to step 1) and perform diagnosis for DTC P1479 (if HFCF PID was yes) or perform diagnosis for DTC P1474 (if LFCF PID was yes). If LFCF PID or HFCF PID indicated NO with fan commanded on or off, primary circuits are okay. Replace LFC relay (if low speed fan is inoperative) or replace HFC relay (if high speed fan is inoperative). Verify 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.
78) Check Operation Of Low Speed Fan Primary Circuits
Reconnect all connectors. Turn ignition on. Connect a test light between VPWR terminal and LFC terminal at LFC relay connector. Using scan tool, access OUTPUT TEST MODE. See OUTPUT TEST MODE under SELF-DIAGNOSTICS. 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 FAN PWR circuit is not shorted to ground. Recheck cooling fan operation. If test light did not turn on then off, LFC primary circuit fault is detected. Go to step 1) and perform diagnosis for DTC P1474.
79) Check Operation Of High Speed Fan Primary Circuits
Reconnect all connectors. Turn ignition on. Connect a test light between VPWR terminal and HFC terminal at HFC relay connector. Using scan tool, access OUTPUT TEST MODE. See OUTPUT TEST MODE under SELF-DIAGNOSTICS. 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 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.
80) Check Operation Of Primary Fan 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 LFC or HFC relay connector. Turn ignition on. Using scan tool, access OUTPUT TEST MODE. See OUTPUT TEST MODE under SELF-DIAGNOSTICS. Perform the appropriate test procedure as follows:
Fan Stops Running With LFC Relay Disconnected
Using scan tool, select LFCA and LFCF PIDs from PID/DATA monitor menu. Command low speed OFF. LFCA PID should read OFF and LFCF PID should read NO.
Fan Stops Running With HFC Relay Disconnected
Using scan tool, select HFCA and HFCF PIDs from PID/DATA monitor menu. Command high speed fan OFF. HFCA PID should read OFF and HFCF PID should read NO.
If LFCF PID or HFCF PID indicated YES with fan commanded OFF, a primary circuit fault is detected. Go to step 1) and perform diagnosis for DTC P1479 (if HFCF PID was yes) or perform diagnosis for DTC P1474 (if LFCF PID was yes). If LFCF PID or HFCF PID indicated NO with fan commanded OFF, primary circuits are okay. Replace LFC relay (if fan stopped running with LFC relay disconnected) or replace HFC relay (if fan stopped running with HFC relay disconnected). Recheck cooling fan operation.
Tuesday, October 30th, 2018 AT 2:38 PM
(Merged)