KF1 DTC P1474/P1477/P1479 or FC PRIMARY CIRCUIT FAULT: CHECK VPWR (or IGN START/RUN for ESCAPE) VOLTAGE TO APPLICABLE FAN CONTROL RELAY
NOTE: During diagnosis, use the chart below to determine the correct circuit and relay being tested.
Disconnect appropriate fan control relay.
Key on, engine off.
Measure VPWR (IGN START/RUN for Escape) circuit voltage at the applicable fan control relay harness connector.
Is voltage greater than 10.5 volts? Yes
GO to KF2
.
No
REPAIR open VPWR (or IGN START/RUN) circuit to the applicable
fan control relay.
KF2 CHECK FOR LFC, MFC or HFC CIRCUIT CYCLING
Key on, engine off.
Connect a non-powered test lamp between the VPWR (or IGN START/RUN) circuit and the LFC, MFC or HFC circuit at the applicable fan control relay harness connector.
Access Output Test Mode on scan tool.
While observing test lamp, command the appropriate cooling fan speed on and off (for Escape, commanding the low speed fan on will also command the medium speed fan output on).
Does the test lamp turn on and off when the cooling fan output is commanded on and off? Yes
REPLACE appropriate fan control relay.
No
REPEAT test step to VERIFY results. If test lamp still does
not turn on and off as expected, turn KEY OFF. REMOVE test lamp. GO to KF3
.
KF3 CHECK LFC, MFC or HFC CIRCUIT FOR SHORT TO POWER IN HARNESS
Disconnect PCM.
Key on, engine off.
Measure voltage between the LFC, MFC or HFC circuit at the applicable fan relay harness connector and ground.
Is voltage less than 1.0 volt? Yes
KEY OFF. GO to KF4
.
No
REPAIR short circuit.
KF4 CHECK LFC, MFC or HFC CIRCUIT FOR SHORT TO GROUND IN HARNESS
Measure resistance between the LFC, MFC or HFC circuit at the applicable fan relay harness connector and ground.
Is resistance greater than 10,000 ohms? Yes
GO to KF5
.
No
REPAIR short circuit.
KF5 CHECK FOR OPEN LFC, MFC or HFC CIRCUIT
Note: Refer to the PCM connector pin numbers at the beginning of this pinpoint test.
Measure resistance of the LFC, MFC or HFC circuit between the appropriate PCM harness connector pin (LFC, MFC or HFC) and the appropriate fan control relay harness connector.
KF7 DTC P1479 (3.0L Escape) CHECK IGNITION START/RUN CIRCUIT VOLTAGE TO HIGH SPEED FC RELAY #1
Disconnect high speed FC relay #1 (MAIN FAN in BJB).
Key on, engine off.
Measure IGN START/RUN circuit voltage at the high speed FC relay #1 harness connector.
Is voltage greater than 10.5 volts? Yes
GO to KF8
.
No
REPAIR open IGN START/RUN circuit.
KF8 CHECK FOR HFC CIRCUIT CYCLING AT HIGH SPEED FC RELAY #1
Connect a non-powered test lamp between the IGN START/RUN circuit and the HFC circuit at the high speed FC relay #1 harness connector.
Access Output Test Mode on scan tool.
While observing test lamp, command the high speed cooling fan on and off.
Does the test lamp turn on and off when the high speed cooling fan output is commanded on and off? Yes
REPLACE high speed FC relay #1.
No
Leave test lamp connected. GO to KF9
.
KF9 CHECK FOR HFC CIRCUIT CYCLING WITH HIGH SPEED FC RELAY #2 DISCONNECTED
The non-powered test lamp still connected between the IGN START/RUN circuit and the HFC circuit at the high speed FC relay #1 harness connector.
Cooling fans commanded off.
Disconnect high speed FC relay #2 (ADD FAN 2 in BJB).
While observing test lamp, again command the high speed cooling fan on and off.
Does the test lamp now turn on and off when the high speed cooling fan output is commanded on and off? Yes
REPLACE high speed FC relay #2.
No
GO to KF3
to diagnose the HFC circuit. Make checks
at the high speed FC relay #1 harness connector.
KF10 CONTINUOUS MEMORY DTC P1474: CHECK LOW SPEED FAN CONTROL (LFC) CIRCUIT FOR OPEN OR SHORT TO POWER
A/C and defrost off.
Disconnect cooling fan connector (both for applications with two fans).
Connect a non-powered test lamp between the (LOW) FAN PWR circuit and ground circuit at the cooling fan harness connector. For applications with two fans, connect light to the following fan harness connector:
Driver's side for 2.0L Escape.
Passenger side for 3.0L Escape.
Other applications with two fans, either one can be used.
Key on, engine off.
Access Output Test Mode on scan tool.
Command Low Speed Fan on.
Observe test lamp for an indication of a fault while completing the following (the lamp will turn off when a fault is detected, indicating an open or short to power):
Shake, wiggle and bend the LFC circuit between the PCM and (low speed) FC relay.
Shake, wiggle and bend the VPWR (or IGN START/RUN) circuit to the (low speed) FC relay.
Lightly tap on the (low speed) FC relay to simulate road shock.
Is a fault indicated? Yes
ISOLATE fault and REPAIR as necessary.
No
GO to KF11
.
KF11 CHECK LFC CIRCUIT FOR SHORT TO GROUND
Key on, engine off.
Command Low Speed Fan off.
Observe test lamp for an indication of a fault while completing the following (the lamp will turn on when a fault is detected, indicating LFC circuit short to ground):
Shake, wiggle and bend the LFC circuit between the PCM and (low speed) FC relay.
Lightly tap on the (low speed) FC relay to simulate road shock.
KF15 CONTINUOUS MEMORY DTC P1477: CHECK MEDIUM SPEED FAN CONTROL (MFC) CIRCUIT FOR OPEN OR SHORT TO POWER
A/C and defrost off.
Disconnect both cooling fans.
For 2.0L Escape:
Connect a non-powered test lamp between the MEDIUM FAN PWR circuit and ground circuit at the passenger side cooling fan harness connector.
For 3.0L Escape:
Disconnect medium speed FC relay (ADD FAN 3, on fan shroud).
Connect a non-powered test lamp between the MFC circuit and IGN START/RUN circuit at the medium speed FC relay harness connector.
Key on, engine off.
Access Output Test Mode on scan tool.
Command Low Speed Fan on (this also commands on the medium speed fan).
Observe test lamp for an indication of a fault while completing the following (the lamp will turn off when a fault is detected, indicating an open or short to power):
Shake, wiggle and bend the LFC circuit between the PCM and medium speed FC relay.
Shake, wiggle and bend the IGN START/RUN circuit to the medium speed FC relay.
For 2.0L, lightly tap on the medium speed FC relay to simulate road shock.
Is a fault indicated? Yes
ISOLATE fault and REPAIR as necessary.
No
GO to KF16
.
KF16 CHECK MFC CIRCUIT FOR SHORT TO GROUND
Key on, engine off.
Command Low Speed Fan off.
Observe test lamp for an indication of a fault while completing the following (the lamp will turn on when a fault is detected, indicating MFC circuit short to ground):
Shake, wiggle and bend the MFC circuit between the PCM and medium speed FC relay.
For 2.0L, lightly tap on the medium speed FC relay to simulate road shock.
For 3.0L, inspect medium speed FC relay for intermittent concerns.
KF20 CONTINUOUS MEMORY DTC P1479: CHECK HIGH SPEED FAN CONTROL (HFC) CIRCUIT FOR OPEN OR SHORT TO POWER
A/C and defrost off.
Disconnect cooling fan connector(s) (both for applications with two fans).
Connect a non-powered test lamp between the (HIGH) FAN PWR circuit and ground circuit at the cooling fan harness connector (for applications with two fans; passenger side for 2.0L Escape, driver's side for 3.0L Escape, either one for others).
Key on, engine off.
Access Output Test Mode on scan tool.
Command High Speed Fan on.
Observe test lamp for an indication of a fault while completing the following (the lamp will turn off when a fault is detected, indicating an open or short to power):
Shake, wiggle and bend the HFC circuit between the PCM and high speed FC relay.
Shake, wiggle and bend the VPWR (IGN START/RUN for Escape) circuit to the high speed FC relay (for 3.0L Escape, both relays).
Lightly tap on the high speed FC relay to simulate road shock.
Is a fault indicated? Yes
ISOLATE fault and REPAIR as necessary.
No
GO to KF21
.
KF21 CHECK HFC CIRCUIT FOR SHORT TO GROUND
Command High Speed Fan off.
Observe test lamp for an indication of a fault while completing the following (the lamp will turn on when a fault is detected, indicating an HFC circuit short to ground):
Shake, wiggle and bend the HFC circuit between the PCM and high speed FC relay.
Lightly tap on the HFC relay to simulate road shock.
KF25 ONE OR ALL FAN SPEEDS INOPERATIVE: CHECK FAN CONTROL FAULT PIDs TO VERIFY FAN CONTROL PRIMARY CIRCUITS
Verify A/C is off, and engine temperature is below the temperature where the cooling fan would come on.
Key on, engine off.
Access the LFCF, MFCF and HFCF PIDs (as appropriate, according to which circuits the vehicle has)(for Escape, early builds will not have the MFCF PID).
Does the LFCF, MFCF or HFCF PID indicate YES? Yes
For the fault PID(s) that are YES, a primary circuit fault is
indicated for that circuit.
For 3.0L Escape with HFCF PID indicating YES:
GO to KF7
.
All others:
GO to KF1
.
No
For Escape:
.
GO to KF85
.
All others:
GO to KF30
.
KF30 ELECTRIC COOLING FAN CONCERN (WITH NO DTCs): CHECK FAN FUNCTION
Key on, engine off.
Access Output Test Mode on scan tool.
Command the cooling fan on and check for fan operation. For two speed fan applications, check both fan speeds (wait 20 seconds after commanding high speed fan on, verify fan speed changes).
COMMAND cooling fan off. REMAIN in Output Test Mode.
For Focus (with A/C), Cougar and Windstar
:
GO to KF50
.
For Focus (without A/C) and Ranger:
Fan will not operate. GO to KF41
.
All others
:
GO to KF31
.
KF31 DID THE FAN(S) OPERATE AT ANY SPEED?
Note: For applications with two cooling fan motors, if one cooling fan motor does not operate when the other motor operates, GO to KF70. During the operational check of both fan speeds, did the fan(s) operate at any speed? Yes
Only one fan speed is operational. GO to KF40
.
No
Cooling fan will not operate at any speed. GO to KF32
.
KF32 COOLING FAN WILL NOT OPERATE AT ANY SPEED: COMMAND HIGH SPEED FAN ON AND CHECK FOR VOLTAGE TO COOLING FAN
Key on, engine off.
Still in Output Test Mode, with fan commanded off.
Disconnect cooling fan(s) (both for applications with two fans).
Command high speed fan on.
Measure voltage between the HIGH FAN PWR circuit at the cooling fan harness connector (either one for Taurus/Sable) and chassis ground.
Is voltage greater than 10.0 volts? Yes
KEY OFF. Power is being supplied to fan.
For Taurus/Sable:
GO to KF130
(to check fan braking relay and ground circuits).
All others:
GO to KF37
(to check cooling fan ground circuit).
No
KEY OFF. Power is not being supplied to fan. GO to KF33
.
KF33 CHECK B+ TO HIGH SPEED FC RELAY AND LOW SPEED FC RELAY
Disconnect high speed and low speed FC relays.
Measure B+ circuit voltage at the high speed FC relay harness connector.
Measure B+ circuit voltage at the low speed FC relay harness connector.
Is voltage greater than 10.0 volts? Yes
GO to KF34
.
No
B+ circuit fault. CHECK condition of related fuses. If OK, REPAIR
open circuit. If fuse is damaged, CHECK B+ and FAN PWR circuits for short
to ground before replacing.
KF34 CHECK FOR OPEN HIGH FAN PWR AND LOW FAN PWR CIRCUITS
Measure resistance of the HIGH FAN PWR circuit between the High Speed FC relay harness connector and the cooling fan harness connector(s). Resistance should be less than 5.0 ohms.
Measure resistance of the LOW FAN PWR circuit between the low speed FC relay harness connector and the cooling fan harness connector(s). Resistance should be less than 5.0 ohms (7.0 ohms for Taurus/Sable).
Do the HIGH FAN PWR and LOW FAN PWR circuits check OK? Yes
GO to KF35
.
No
REPAIR open circuit (for Taurus/Sable, if open is in LOW FAN
PWR circuit, verify condition of resistor that is in circuit).
KF35 COMMAND LOW SPEED FAN ON AND CHECK FOR VOLTAGE TO COOLING FAN
Reconnect low speed FC relay and high speed FC relay.
Key on, engine off.
Again, enter Output Test Mode on scan tool.
Command Low Speed Fan on.
Measure LOW FAN PWR circuit voltage at the cooling fan harness connector (either one for applications with two fans).
Is voltage greater than 10.0 volts? Yes
KEY OFF. REPLACE the High Speed FC relay, then GO to KF37
(for
Taurus/Sable, GO to KF130
).
No
KEY OFF. GO to KF75
, and follow directions for low
speed fan inoperative. After repair, GO to KF75
and follow directions
for high speed fan inoperative.
