Ford F150 Pickup. Manual - part 1574

 
This test checks the Fan Control - Variable (FCV) output circuit. The DTC sets if the PCM detects that 
the voltage on the FCV circuit is not within the expected range. Possible causes are: 

z

FCV circuit open or shorted.  

z

B+ or ground circuit fault to cooling fan.  

z

VPWR open to cooling fan (if applicable).  

z

Damaged cooling fan module.  

z

Damaged PCM.  

Turn ignition switch to OFF position. Disconnect cooling fan motor connector. Using a DVOM, measure 
voltage between B+ and ground circuits at the cooling fan motor harness connector. See Fig. 350 or Fig. 
351 . If voltage is greater than 10.5 volts, go to step 23). If voltage is 10.5 volts or less, go to next step. 

21) Check B+ Voltage To Fan Motor Using Chassis Ground As Reference 
 
Using a DVOM, measure voltage between B+ at the cooling fan motor harness connector and chassis 
ground. If voltage is greater than 10.5 volts, repair open ground circuit. If voltage is 10.5 volts or less, 
verify integrity of related fuse. If fuse is okay, repair open B+ circuit. If fuse is damaged, check B+ circuit 
for short to ground before replacing. 

23) Check VPWR To Cooling Fan Controller 
 
Turn ignition switch to OFF position. Disconnect cooling fan controller. Turn ignition switch to OFF 
position. Using a DVOM, measure VPWR voltage at the cooling fan controller harness connector. See 
Fig. 352. If voltage is greater than 10.5 volts, turn ignition switch to OFF position and go to next step. If 
voltage is 10.5 volts or less, repair open circuit. 

24) Check FCV Circuits To Fan 
 
Connect 1.6 k/ohm resistor between the FCV and VPWR circuits at the cooling fan controller harness 
connector (this simulates cooling fan circuitry). If a DVOM that measures duty cycle (percent) is 
available: Connect DVOM between FCV circuit at the cooling fan controller harness connector (red 
probe) and ground (black probe). Set DVOM to measure percent positive duty cycle. Turn ignition switch 
to ON position. Perform KOEO ON-DEMAND SELF-TEST. During KOEO Self-Test, if the duty cycle 
changes from approximately 10 percent to approximately 90 percent (or is DTC P0480 not present), 
replace cooling fan module. If DTC P0480 is still present or duty cycle did not change as expected, go to 
next step. 

25) Check FCV Circuit For Short To Power In Harness 
 
Turn ignition switch to OFF position. Disconnect PCM. Turn ignition switch to ON position. Using a 
DVOM, measure voltage between FCV circuit at the cooling fan controller harness connector and ground. 
If voltage is less than 1.0 volt, turn ignition switch to OFF position and go to next step. If voltage is 1.0 
volt or more, repair short circuit. 

26) Check FCV Circuit For Short To Ground In Harness 

 

2003 Ford Pickup F150 

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

  

 
Disconnect scan tool from DLC. Using a DVOM, measure resistance between FCV circuit at the cooling 
fan controller harness connector and ground. If resistance is greater than 10 k/ohms, go to next step. If 
resistance is not greater than 10 k/ohms, repair short circuit. 

27) Check For Open FCV Circuit 
 
Using a DVOM, measure resistance of the FCV circuit between the PCM and the cooling fan controller 
harness connector. If resistance is less than 5.0 ohms, replace PCM. If resistance is 5.0 ohms or more, 
repair open circuit. 

30) For Continuous Memory Only DTC P0480 & P1474: Check For Intermittent B+ And Ground 
To Cooling Fan Motor 
 
This test checks the Fan Control - Variable (FCV) output circuit. The DTC sets if the PCM detects that 
the voltage on the FCV circuit is not within the expected range. Possible causes are: 

z

FCV circuit open or shorted.  

z

B+ or ground circuit fault to cooling fan.  

z

VPWR open to cooling fan (if applicable).  

z

Damaged cooling fan module.  

z

Damaged PCM.  

Turn ignition switch to OFF position. Disconnect cooling fan motor connector. Connect a non-powered 
test light between the B+ and ground circuits at the cooling fan motor harness connector. See Fig. 350 or 
Fig. 351 . Observe test light for an indication of a fault while performing the following (the lamp will turn 
off when a fault is detected):  

z

Shake, wiggle, bend the B+ and ground circuits to the cooling fan motor connector.  

z

Lightly tap/wiggle the associated fuse.  

If a fault is indicated, isolate fault and repair as necessary. If a fault is not indicated, go to next step. 

31) Check For Intermittent VPWR Circuit To Cooling Fan Controller 
 
Turn ignition switch to OFF position. Disconnect cooling fan controller connector. Connect a non-
powered test light between the VPWR circuit at the cooling fan controller harness connector and ground. 
See Fig. 352. Turn ignition switch to ON position. Observe test light for an indication of a fault while 
performing the following (the lamp will turn off when a fault is detected): shake, wiggle, bend the VPWR 
circuit to the cooling fan controller connector. If a fault is indicated, isolate fault and repair as necessary. 
If a fault is not indicated, go to next step. 

32) Check For Intermittent FCV Circuit To Cooling Fan 
 

NOTE:

A break in step numbering sequence occurs at this point. Procedure skips 
from step 27) to step 30). No test procedures have been omitted.

 

2003 Ford Pickup F150 

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

  

Connect 1.6 k/ohm resistor between the FCV and VPWR circuits at the cooling fan controller harness 
connector (this simulates cooling fan circuitry). Connect a DVOM between FCV circuit at the cooling fan 
controller harness connector and ground. Turn ignition switch to ON position. Using scan tool, access 
OUTPUT TEST MODE. See OUTPUT TEST MODE under ADDITIONAL SYSTEM FUNCTIONS. 
Command low speed cooling fan on. Observe DVOM for an indication of a fault while performing the 
following (the DVOM volts will change suddenly when a fault is detected): shake, wiggle, bend the FCV 
circuit between the cooling fan and PCM. If a fault is indicated, turn ignition switch to OFF position and 
isolate fault and repair as necessary. If a fault is not indicated, turn ignition switch to OFF position and go 
to TEST Z, step 1).  

TEST KP: CHARGE AIR COOLER PUMP 

Diagnostic Aids 

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

z

Charge Air Cooler (CAC) pump relay.  

z

CAC pump motor.  

z

Fuse No. 23 (15-Amp) & fuse No. 106 (20-amp), located in battery junction box.  

z

Wiring harness circuits (B+, CAC, CAC PUMP PWR & VPWR). See Fig. 353.  

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

 

2003 Ford Pickup F150 

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

  

Fig. 353: Identifying Charge Air Cooler Pump Circuits & Connector Terminals 
Courtesy of FORD MOTOR CO. 

Testing 

 

2003 Ford Pickup F150 

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