Ford F150 Pickup. Instruction — part 1586

CCRM between terminals No. 15 and 17 (it may be necessary to switch the Red and Black DVOM
probes to get resistance reading greater than 1000 ohms). Each resistance should be more than 1000
ohms. If all resistances are as specified, leave CCRM disconnected and go to next step. If any resistance
is not as specified, replace CCRM.

16) Check For Open In HFC Circuit

Turn ignition switch to OFF position. Disconnect PCM connector. Inspect connector for loose, damaged
or corroded terminals. Repair as necessary. Using a DVOM, measure resistance of HFC circuit between
CCRM harness connector and PCM harness connector. See Fig. 372-Fig. 375 . If resistance is less than 5
ohms, go to next step. If resistance is 5 ohms or more, repair open in HFC circuit.

17) Check HFC Circuit For Short To PWR In Harness

Turn ignition switch to ON position. Using a DVOM, measure voltage between chassis ground and HFC
circuit at PCM harness connector. If voltage is less than one volt, go to next step. If voltage is one volt or
more, repair short to PWR in HFC circuit.

18) Check HFC Circuit For Short To Ground In Harness

Turn ignition switch to OFF position. Disconnect scan tool from Data Link Connector (DLC). Using a
DVOM, measure resistance between chassis ground and HFC circuit at PCM harness connector. See Fig.
372-Fig. 375 . If resistance is 10 k/ohms or less, repair short to ground in HFC circuit. If resistance is
more than 10 k/ohms and DTC P1479 was not retrieved, replace CCRM and verify HIGH FAN PWR
circuit is not shorted to ground. If resistance is more than 10 k/ohms and you were directed here to
diagnose DTC P0481 or P1479, connect scan tool to DLC. Turn ignition switch to ON position. Using
scan tool, access OUTPUT TEST MODE. See OUTPUT TEST MODE under ADDITIONAL SYSTEM
FUNCTIONS. Command high speed fan ON, wait 10 seconds and then command high speed fan OFF. If
high speed fan turns on and off, disregard DTC P0481 or P1479, repeat QUICK TEST and service any
DTCs as necessary. If high speed fan does not turn on and off, replace PCM.

20) For KOEO & KOER Only DTC P0480 & P1474: Check Fan Operation
DTC P0480 and P1474 indicate primary circuit failure in Low Fan Control (LFC) circuit or Fan Control
(FC) circuit for single cooling fan systems. Possible causes are:

z

Open Or Shorted FC/LFC Circuit

z

Open VPWR Circuit To LFC Relay

z

Faulty CCRM (Low Speed Fan Control Relay)

z

Faulty PCM

Turn ignition switch to ON position. If cooling fan runs continuously, go to step 24). If cooling fan does

NOTE:

A break in step numbering sequence occurs at this point. Procedure skips
from step 18) to step 20). No test procedures have been omitted.

NOTE:

For additional testing information, see DIAGNOSTIC AIDS.

2003 Ford Pickup F150

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

not run continuously, go to next step.

21) Check FC/LFC Circuit For Short To Ground In Harness

Turn ignition switch to OFF position. Disconnect CCRM connector. Disconnect scan tool from Data Link
Connector (DLC). Disconnect PCM connector. Inspect connector for loose, damaged or corroded
terminals. Repair as necessary. Using a DVOM, measure resistance between chassis ground and FC/LFC
circuit at CCRM harness connector terminal No. 14. See Fig. 372-Fig. 375 . If resistance is more than 10
k/ohms, go to next step. If resistance is 10 k/ohms or less, repair FC/LFC circuit for short to ground.

22) Check Fan Running Mode

Connect CCRM connector. Leave PCM disconnected. Turn ignition switch to ON position. If cooling fan
runs continuously, replace PCM. If cooling fan does not run continuously, replace CCRM.

24) Check For Open In FC/LFC Circuit In Harness

Turn ignition switch to OFF position. Disconnect CCRM connector. Disconnect PCM connector. Inspect
connector for loose, damaged or corroded terminals. Repair as necessary. Using a DVOM, measure
resistance of FC/LFC circuit between CCRM harness connector and PCM harness connector. See PCM
CONNECTOR IDENTIFICATION and Fig. 372-Fig. 375 . If resistance is less than 5 ohms, go to next
step. If resistance is 5 ohms or more, repair open in FC/LFC circuit.

25) Check FC/LFC Circuit For Short To PWR In Harness

Turn ignition switch to ON position. Using a DVOM, measure voltage between chassis ground and
FC/LFC circuit at CCRM harness connector terminal No. 14. If voltage is less than one volt, go to next
step. If voltage is one volt or more, repair short to B+ Or VPWR in FC/LFC circuit.

26) FC/LFC Circuit Fault Isolation Check

Turn ignition switch to OFF position. Reconnect CCRM connector. Connect a jumper wire between
chassis ground and FC/LFC circuit at PCM harness connector. See PCM CONNECTOR
IDENTIFICATION and Fig. 372-Fig. 375 . If cooling fan continues to run, replace CCRM. If cooling
fan does not continue to run, replace PCM.

NOTE:

A break in step numbering sequence occurs at this point. Procedure skips
from step 22) to step 24). No test procedures have been omitted.

NOTE:

A break in step numbering sequence occurs at this point. Procedure skips
from step 26) to step 30). No test procedures have been omitted.

NOTE:

For additional testing information, see DIAGNOSTIC AIDS.

NOTE:

FC/LFC circuit is grounded to turn cooling fan off.

2003 Ford Pickup F150

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

30) For Continuous Memory Only DTC P0480 & P1474: Check FC/LFC Circuit For Open Or
Short To PWR
DTC P0480 & P1474 indicates primary circuit failure in Low Fan Control (LFC) circuit or Fan Control
(FC) circuit for single cooling fan systems. Possible causes are:

z

Open Or Shorted FC/LFC Circuit

z

Open VPWR Circuit To LFC Relay

z

Faulty CCRM (Low Speed Fan Control Relay)

z

Faulty PCM

Turn ignition switch to OFF position. Disconnect cooling fan connector. Connect a test light between
negative battery terminal and LOW FAN PWR circuit (FAN PWR circuit on Mustang 3.8L) at cooling
fan harness connector. See

Fig. 372

-Fig. 373 . Turn ignition switch to ON position. Test light should be

off. Check for indication of a fault while performing the following:

z

Shake, wiggle and bend FC/LFC circuit between CCRM and PCM.

z

Lightly tap CCRM to simulate road shock.

A fault (open or short to PWR in FC/LFC circuit) is indicated when test light blinks or is illuminated. If
fault is indicated, isolate fault and repair as necessary. If fault is not indicated, go to next step.

31) Check FC/LFC Circuit For Short To Ground

Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Leave cooling
fan connector disconnected and test light connected. 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. Test light should illuminate. Check for indication of a
fault while performing the following:

z

Shake, wiggle and bend FC/LFC circuit between CCRM and PCM.

z

Lightly tap CCRM to simulate road shock.

A fault (short to ground in FC/LFC circuit or open in VPWR circuit) is indicated when test light turns off.
If fault is indicated, isolate fault and repair as necessary. If fault is not indicated, concern is intermittent
and cannot be duplicated at this time. Go to TEST Z, step 1) and check for intermittent faults.

35) For Continuous Memory Only DTC P0481 & P1479: Check High Speed Fan Control Circuit
For Open Or Short To PWR
DTC P0481 & P1479 indicate primary circuit failure in High Speed Fan Control (HFC) circuit. Possible
causes are:

NOTE:

A break in step numbering sequence occurs at this point. Procedure skips
from step 31) to step 35). No test procedures have been omitted.

NOTE:

For additional testing information, see DIAGNOSTIC AIDS.

NOTE:

On single-speed cooling fan applications, ignore DTCs P0481 and P1479.

2003 Ford Pickup F150

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

z

Open Or Shorted HFC Circuit

z

Open VPWR Circuit To HFC Relay

z

Faulty CCRM (High Speed Fan Control Relay Or Internal Circuit)

z

Faulty Powertrain Control Module (PCM)

Turn ignition switch to OFF position. Disconnect cooling fan connector. Inspect connector for loose,
damaged or corroded terminals. Repair as necessary. Connect a test light between negative battery
terminal and HIGH FAN PWR circuit terminal at cooling fan harness connector. See Fig. 373 or Fig.
374 . Turn ignition switch to ON position. Using scan tool, access OUTPUT TEST MODE. See
OUTPUT TEST MODE under ADDITIONAL SYSTEM FUNCTIONS. Command HIGH SPEED FAN
ON. Test light should illuminate. Check for indication of a fault while performing the following:

z

Shake, wiggle and bend HFC circuit between CCRM and PCM.

z

Lightly tap CCRM to simulate road shock.

A fault (open or short to PWR in HFC circuit) is indicated when test light turns off. If fault is indicated,
isolate fault and repair as necessary. If fault is not indicated, go to next step.

36) Check HFC Circuit For Short To Ground

Turn ignition switch to ON position. Using scan tool, command HIGH SPEED FAN OFF. Test light
should be off. Check for indication of a fault while performing the following:

z

Shake, wiggle and bend HFC circuit between CCRM and PCM.

z

Lightly tap CCRM to simulate road shock.

A fault (short to ground in HFC circuit) is indicated when test light illuminates. If fault is indicated,
isolate fault and repair as necessary. If fault is not indicated, concern is intermittent and cannot be
duplicated at this time. Go to TEST Z, step 1) and check for intermittent faults.

40) Electric Cooling Fan Functional Check
Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition
switch to ON position. Using scan tool, access OUTPUT TEST MODE. See OUTPUT TEST MODE
under ADDITIONAL SYSTEM FUNCTIONS. Command cooling fan ON and check cooling fan
operation. On 2-speed cooling fan applications, check both fan speeds (wait 30 seconds after

NOTE:

A break in step numbering sequence occurs at this point. Procedure skips
from step 36) to step 40). No test procedures have been omitted.

NOTE:

For proper results of the following test step, no DTCs must have been
present during QUICK TEST.

NOTE:

Diagnostic procedures beginning with step 40) are performed when
directed here from ELECTRIC COOLING FAN DOES NOT RUN AT LOW,
MEDIUM &/OR HIGH SPEED under SYMPTOMS in TROUBLE SHOOTING -
NO CODES - CNG & GASOLINE article.

2003 Ford Pickup F150

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