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