Ford F150 Pickup. Instruction — part 1573

Fig. 351: Identifying Cooling Fan Motor Harness Connector Terminals (LS & Thunderbird)
Courtesy of FORD MOTOR CO.

2003 Ford Pickup F150

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

Fig. 352: Identifying Cooling Fan Controller Circuits & Connector Terminals (LS & Thunderbird)
Courtesy of FORD MOTOR CO.

Testing

1) For KOEO & KOER Only DTC P0480 & P1474: Check B+ And Ground To Cooling Fan

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. Using a DVOM, measure voltage between
B+ and ground circuits at the cooling fan harness connector. See Fig. 350 or Fig. 351 . If voltage is
greater than 10.5 volts, go to step 5). If voltage is 10.5 volts or less, go to next step.

2) Check B+ Voltage To Fan Using Chassis Ground As Reference

Using a DVOM, measure voltage between B+ at the cooling fan 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.

5) Check FCV Circuits To Fan

Connect 1.6 k/ohm resistor between the FCV and B+ circuits at the cooling fan harness connector (this

NOTE:

A break in step numbering sequence occurs at this point. Procedure skips
from step 2) to step 5). No test procedures have been omitted.

2003 Ford Pickup F150

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

simulates cooling fan circuitry). See Fig. 350, or Fig. 351 and Fig. 352 . Turn ignition switch to ON
position. Perform KOEO ON-DEMAND SELF-TEST. If KOEO DTC P0480 or P1474 is still present,
go to next step. If KOEO DTC P0480 or P1474 is not present, replace cooling fan module.

6) 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 harness connector and ground. If voltage
is less than 1.0 volt, to next step. If voltage is 1.0 volt or more, repair short circuit.

7) Check FCV Circuit For Short To Ground In Harness

Turn ignition switch to OFF position. Disconnect scan tool from DLC. Using a DVOM, measure
resistance between FCV circuit at the cooling fan 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.

8) Check For Open FCV Circuit

Using a DVOM, measure resistance of the FCV circuit between the PCM and the cooling fan harness
connector. If resistance is less than 5.0 ohms, replace PCM. If resistance is 5 ohms or more, repair open
circuit.

10) For Continuous Memory Only DTC P0480 & P1474: Check For Intermittent B+ And Ground
To Cooling Fan

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. Connect a non-powered test light between
the B+ and ground circuits at the cooling fan 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.

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.

NOTE:

A break in step numbering sequence occurs at this point. Procedure skips
from step 8) to step 10). No test procedures have been omitted.

2003 Ford Pickup F150

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

11) Check For Intermittent FCV Circuit To Cooling Fan

Connect 1.6 k/ohm resistor between the FCV and B+ circuits at the cooling fan harness connector (this
simulates cooling fan circuitry). See Fig. 350, or Fig. 351 and Fig. 352 . Connect DVOM between FCV
circuit at the cooling fan 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 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, isolate fault and repair as necessary.
If no fault is indicated, turn ignition switch to OFF position. Go to TEST Z, step 1).

15) Cooling Fan Does Not Operate (With No DTCs): Command Fan On To Check Operation
While listening to cooling fan, perform KOEO ON-DEMAND SELF-TEST. If the fan runs sometime
during KOEO self-test, turn ignition switch to OFF position. Return to ELECTRIC, HYDRAULIC OR
VISCTRONIC COOLING FAN INOPERATIVE under SYMPTOMS in TROUBLE SHOOTING -
NO CODES - CNG, FLEX-FUEL & GASOLINE article to continue diagnosing low idle concern. Repair
as necessary. If the fan does not run during KOEO self-test, turn ignition switch to OFF position and go
to next step.

16) Check B+ And Ground To Cooling Fan

Disconnect cooling fan (cooling fan motor connector for LS and Thunderbird). 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, replace cooling fan module/assembly. If voltage is 10.5 volts or less, go to next
step.

17) Check B+ To Fan 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.

20) For KOEO & KOEO Only DTC P0480 & P1474: Check B+ And Ground To Cooling Fan
Motor

NOTE:

A break in step numbering sequence occurs at this point. Procedure skips
from step 11) to step 15). No test procedures have been omitted.

NOTE:

Step 15) is performed when directed here from ELECTRIC, HYDRAULIC OR
VISCTRONIC COOLING FAN INOPERATIVE symptom under SYMPTOMS in
TROUBLE SHOOTING - NO CODES - CNG, FLEX-FUEL & GASOLINE
article.

NOTE:

A break in step numbering sequence occurs at this point. Procedure skips
from step 17) to step 20). No test procedures have been omitted.

2003 Ford Pickup F150

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