Download (no dtcs): check the fan control primary circuits

P0480 - Fan 1 Control Circuit
For Relay Controlled Electric Cooling Fan
Description: Monitors the low fan control (LFC) primary circuit output from the
powertrain control (PCM). The test fails when the PCM grounds the LFC circuit and
excessive current draw is detected on the LFC circuit; or with the LFC circuit not
grounded by the PCM the voltage is not detected on the LFC circuit (the PCM expects to
detect VPWR voltage coming through the low speed fan control relay coil to the LFC
circuit).
Possible Causes:



Open or short LFC circuit
Open VPWR circuit to the low speed FC relay
Damaged low speed FC relay
Diagnostic Aids: When the LFC PID reads YES, a concern is currently present. During
the key on engine off (KOEO) self-test, the cooling fan is cycled on and off. A short to
voltage can only be detected when the PCM is grounding the LFC circuit. During the
KOEO and key on engine running (KOER) self-test, the LFC circuit is cycled on and off.
For Variable Speed Electric Cooling Fan
Description: This test checks the fan control-variable (FCV) output circuit. The DTC
sets if the powertrain control module (PCM) detects the voltage on the FCV circuit is not
within the expected range.
Possible Causes:




FCV circuit open or short
B+ or ground circuit concern to cooling fan
VPWR open to cooling fan (if applicable)
Damaged cooling fan module
Diagnostic Aids: During the key on engine off (KOEO) self-test, the cooling fan is
cycled on and off.
For Cooling Fan Clutch
Description: This test checks the fan control-variable (FCV) output circuit for the
cooling fan clutch. The DTC sets if the powertrain control module (PCM) detects the
voltage on the FCV circuit is not within the expected range.
Possible Causes:


FCV circuit open in the harness
FCV circuit short to voltage or ground in the harness

Damaged cooling fan clutch solenoid.
Diagnostic Aids: During the key on engine off (KOEO) self-test, the cooling fan is
cycled on and off.
Application
Key On
Engine Off
Key On Engine
Running
Relay Controlled Electric
Cooling Fan
GO to Pinpoint Test KF.
Variable Speed Electric
Cooling Fan
GO to Pinpoint Test KN.
Cooling Fan Clutch
GO to Pinpoint Test HV.
Continuous
Memory
KF47 COOLING FAN CONCERN (NO DTCS): CHECK THE FAN CONTROL PRIMARY CIRCUITS
Note: Chose the PIDs below as appropriate, according to which circuits the
vehicle has.


Verify that the A/C is OFF.
Verify engine temperature is below the temperature where the cooling fan comes
on.
 Key ON, engine OFF.
 Access the PCM and monitor the LFC_F, MFC_F and HFC_F PIDs.
Does either PID indicate a concern?
Yes
A concern is present in the
primary circuit(s).
GO to KF48.
No
For all except Ranger, the PCM primary circuit(s) is
OK.
To check for secondary wiring,
REFER to the Workshop Manual Section 303-03,
Engine Cooling, for cooling system diagnosis.
For Ranger:
GO to KF50.
KF48 DOES THE LFCF PID INDICATE A CONCERN?
Does the LFCF PID indicate a concern?
Yes
No
The low fan control (LFC) circuitry has a primary circuit concern.
GO to KF49.
GO to KF3.
KF49 DOES THE MFCF PID INDICATE A CONCERN?
Does the MFCF PID indicate a concern?
Yes
The medium fan control (MFC) primary
circuitry has a circuit concern.
For Focus, GO to KF18.
For all others, GO to KF8.
No
The high fan control (HFC) primary
circuitry has a circuit concern.
For Escape 3.0L, and
Mariner 3.0L, GO to KF27.
For all others, GO to KF13.