Ford F150 Pickup. Instruction - part 1566

between chassis ground and PCM harness connector terminal No. 86 (Black/Yellow wire). If resistance is 
more than 10 k/ohms, replace PCM. If resistance is 10 k/ohms or less, repair short to ground in 
Black/Yellow wire. Recheck cooling fan operation. 

154) Check LFC (Fan Braking) Relay 
 
Turn ignition switch to OFF position. Remove LFC (fan braking) relay. See COOLING FAN RELAY 
LOCATIONS table. If cooling fans stop operating, replace LFC (fan braking) relay. Recheck cooling fan 
operation. If fans do not stop operating, go to step 156). 

155) Check Circuit Light Blue wire For A Short To Ground. 
 
Turn ignition switch to OFF position. Disconnect: PCM connector. Measure the resistance between PCM 
connector No. 28 (Light Blue wire) and ground. If the resistance is greater than 10 k/ohms, go to next 
step. If resistance is not greater than 10 k/ohms, install a new engine wiring harness. Test the system for 
normal operation 

156) Check Light Green/Violet & Red/Orange Wires At MFC (Resistor Relay) & For Short To 
PWR 
 
Remove MFC (resistor) relay. If cooling fans stop operating, repair short to PWR in Light Green/Violet 
wire between MFC (resistor) relay and LFC (fan braking) relay. See WIRING DIAGRAMS. Recheck 
cooling fan operation. If cooling fans do not stop operating, repair short to PWR in Red/Orange wire 
between MFC (resistor) relay and cooling fans. See WIRING DIAGRAMS. Recheck cooling fan 
operation. 

162) Check Operation Of The Electric Cooling Fan 
 
Using scan tool, command the cooling fan ON. If the cooling fan operates, cooling fan system is okay. 
Go to appropriate symptom under SYMPTOMS in TROUBLE SHOOTING - NO CODES - CNG, 
FLEX-FUEL & GASOLINE article. If the cooling fan does not operate, go to next step. 

163) Check The Cooling Fan Relay 
 
Remove the electric cooling fan relay. Using a DVOM, measure resistance between specified relay 
terminals. See MINI ISO RELAY RESISTANCE SPECIFICATIONS table. See Fig. 306. If relay 
resistance is not as specified, replace electric cooling fan relay. If relay resistance is as specified, connect 
2 jumper wires from positive battery terminal to relay terminals No. 30 and 85. Connect another jumper 
from relay terminal No. 86 to chassis ground. Using a DVOM, measure voltage between relay terminals 
No. 86 and 87. If battery voltage is not present at relay terminal No. 87, replace cooling fan relay. 
Recheck cooling fan operation. If the cooling fan relay passed the component test, go to next step. 

164) Check Voltage To The Cooling Fan Relay 
 
Using a DVOM, measure the voltage between the cooling fan relay connector terminal No. 30 
(Red/Black wire) harness side and ground. If the voltage is greater than 10 volts, go to next step. If the 
voltage is 10 volts or less, repair Red/Black wire as necessary. Test the system for normal operation. 

 

2003 Ford Pickup F150 

2003 ENGINE PERFORMANCE Self-Diagnostics - CNG, Flex-Fuel & Gasoline

  

165) Check The Voltage To The Electric Cooling Fan 
 
Install cooling fan relay. Disconnect the fan motor harness connector. Using scan tool, cycle the cooling 
fan on. Using DVOM, measure the voltage between the cooling fan motor connector terminal No. 1 
(Yellow/Black wire) and ground. If the voltage is greater than 10 volts, go to next step. If the voltage is 
10 volts or less, repair Yellow/Black wire as necessary. Test the system for normal operation. 

166) Check Cooling Fan 
 
Connect a fused jumper wire (20A) between the positive battery terminal and the cooling fan motor 
connector terminal No. 1, and connect a fused jumper wire (20A) between the negative battery terminal 
and the cooling fan motor connector terminal No. 2 on the component side. If the cooling fan operates, go 
to next step. If the cooling does not operate, install a new cooling fan motor. Test the system for normal 
operation. 

167) Check Fan Motor Ground Circuit (Black Wire) 
 
Using a DVOM, measure the resistance between the electric cooling fan connector terminal No. 2 (Black 
wire) and ground. If the resistance is less than 5 ohms, test the system for normal operation. If the 
resistance is 5 ohms or more, repair Black wire between electric cooling fan connector and ground. Test 
the system for normal operation.  

TEST KG: VISCTRONIC DRIVE FAN CLUTCH 

Diagnostic Aids 

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

z

Visctronic Drive Fan Clutch. See Fig. 332.  

z

Visctronic Drive Fan Speed Sensor  

z

Wiring Harness Circuits Fan Control-Variable (FC-V), Fan Speed Sensor (FSS), PWRGND, Vehicle 
Buffered Power (VBPWR) & VPWR. See Fig. 333.  

z

Powertrain Control Module (PCM)  

FANSS PID will indicate fan RPM, and FANSSM will indicate if Hall Effect sensor for VDF fan speed is 
always HIGH or always LOW. 

NOTE:

After each service or repair procedure has been completed, reconnect all 
components. Clear DTCs and repeat QUICK TEST procedures to ensure all EEC-
V systems are working properly and DTCs are no longer present.

 

2003 Ford Pickup F150 

2003 ENGINE PERFORMANCE Self-Diagnostics - CNG, Flex-Fuel & Gasoline

  

Fig. 332: Identifying Visctronic Drive Fan Clutch 
Courtesy of FORD MOTOR CO. 

 

2003 Ford Pickup F150 

2003 ENGINE PERFORMANCE Self-Diagnostics - CNG, Flex-Fuel & Gasoline

  

Fig. 333: Identifying Visctronic Drive Fan Clutch Harness Circuits & Connector Terminals 
Courtesy of FORD MOTOR CO. 

Testing 

1) For KOEO, KOER & Continuous Memory DTC P0480: Check DTCs 
DTC P0480 is set when PCM detects voltage too high or too low, when compared to expected voltage 
range of (VDF) primary circuit. Possible causes are: 

z

FC-V Circuit Open  

z

FC-V Circuit Short To Power  

z

FC-V Circuit Short To Ground  

z

Faulty VDF Solenoid  

z

Faulty PCM  

If only Continuous Memory DTC P0480 is present, go to next step. If KOEO or KOER DTC P0480 is 
also present, go to step 4). 

2) Access FANVAR_F PID 
Turn ignition switch to ON position. Using scan tool and access FANVARF PID from PID/DATA 
MONITOR & RECORD menu. Wiggle VDF harness and connector while monitoring FANVARF PID. If 

NOTE:

For additional testing information, see DIAGNOSTIC AIDS.

NOTE:

Depending on scan tool, FANVAR_F PID may be named VFCF.

NOTE:

A break in step numbering sequence occurs at this point. Procedure skips 
from step 2) to step 4). No test procedures have been omitted.

 

2003 Ford Pickup F150 

2003 ENGINE PERFORMANCE Self-Diagnostics - CNG, Flex-Fuel & Gasoline