Ford F150 Pickup. Instruction - part 1572

 
Turn ignition switch to OFF position. Disconnect scan tool from Data Link Connector (DLC). Using a 
DVOM, measure resistance between chassis ground and A/C clutch relay circuit at A/C clutch relay 
cavity. If resistance is more than 10 k/ohms, go to next step. If resistance is 10 k/ohms or less, repair short 
to ground in A/C clutch relay circuit. Start engine and allow to idle. Turn A/C on and wait 15 seconds. 
Turn A/C off and repeat QUICK TEST to verify repair. 

6) Check A/C Clutch Relay Circuit For Open In Harness 
 
Using a DVOM, measure resistance of A/C clutch relay circuit between PCM harness connector and A/C 
clutch relay cavity. See Fig. 306 or Fig. 307 and Fig. 339-Fig. 341 . If resistance is less than 5 ohms, 
replace PCM. Start engine and allow to idle. Turn A/C on and wait 15 seconds. Turn A/C off and repeat 
QUICK TEST to verify repair. If resistance is 5 ohms or more, repair open in A/C clutch relay circuit. 
Start engine and allow to idle. Turn A/C on and wait 15 seconds. Turn A/C off and repeat QUICK TEST
to verify repair. 

10) ACCS PID OFF With A/C On: Verify A/C Clutch Is Getting PWR 
Start engine and allow to idle. Listen for A/C clutch to engage while turning A/C on. If clutch can be 
heard engaging, go to next step. If A/C clutch cannot be heard, turn ignition switch to OFF position. 
Disconnect A/C clutch connector. Connect test light between PWR and GND circuits at A/C clutch 
harness connector. Again, start engine and allow to idle. Turn A/C on. If test light illuminates, PWR is 
being supplied to A/C clutch, but ACCS PID value reads OFF. Go to next step. If test light does not 
illuminate, ACCS PID is OFF due to PWR not being supplied to A/C clutch. A/C clutch is not cause of 
low idle symptom. Return to LOW IDLE (STALLS ON DECELERATION) under SYMPTOMS in 
TROUBLE SHOOTING - NO CODES - CNG, FLEX-FUEL & GASOLINE article to continue 
diagnosing low idle concern. Repair as necessary. If a low idle symptom is not the concern and A/C 
clutch operates normally, see appropriate A/C-HEATER SYSTEMS article in AIR CONDITIONING & 
HEATING. 

11) Check ACCS Circuit For Open In Harness 
 
Turn ignition switch to OFF position. Disconnect A/C clutch connector, if not done previously. 
Disconnect PCM connector. Inspect connectors for loose, damaged or corroded terminals. Repair as 
necessary. Using a DVOM, measure resistance of ACCS circuit between PCM harness connector and 
A/C clutch harness connector. See PCM CONNECTOR IDENTIFICATION and Fig. 342, Fig. 343, 
Fig. 345-Fig. 347 or Fig. 349 . If resistance is less than 5 ohms, replace PCM. If resistance is 5 ohms or 
more, repair open in ACCS circuit between A/C clutch and PCM. 

NOTE:

A break in step numbering sequence occurs at this point. Procedure skips 
from step 6) to step 10). No test procedures have been omitted.

NOTE:

Diagnostic procedures beginning with step 10) are performed when 
directed here from LOW IDLE WITH A/C ON (Econoline 4.6L, 5.4L and 6.8L 
only) symptom under SYMPTOMS in TROUBLE SHOOTING - NO CODES - 
CNG, FLEX-FUEL & GASOLINE article.

 

2003 Ford Pickup F150 

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

  

19) For KOEO & KOER Only DTC P1464: Check ACCS PID 
DTC P1464 can be set if A/C or defroster is on during KOEO or KOER self-test. DTC P1464 is set when 
ACCS input to PCM was high during self-test. Possible causes for this fault are: 

z

A/C On During Self-Test  

z

Short To VPWR In A/C Clutch VPWR Circuit (Applications With Normally Closed A/C clutch 
relay)  

z

ACCS Circuit Shorted To PWR  

z

Faulty A/C Demand Switch  

z

Faulty WAC Relay (Or CCRM)  

z

Faulty PCM  

Turn ignition switch to ON position. Using scan tool, access ACCS PID from PID/DATA MONITOR & 
RECORD menu. If ACCS PID value indicates ON, go to next step (Econoline except 4.2L), go to 
appropriate A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING to diagnose A/C 
ALWAYS ON symptom (all others). If ACCS PID value indicates OFF, this indicates that ACCS input to 
PCM is low. Verify self-test results. Leave A/C and defroster off and repeat QUICK TEST. 

20) ACCS PID ON: Disconnect A/C Cycling Switch & Check If ACCS PID Indicates OFF 
 
Turn ignition switch to OFF position. Disconnect A/C cycling switch. Turn ignition switch to ON 
position. Using scan tool, access ACCS PID from PID/DATA MONITOR & RECORD menu. If ACCS 
PID indicates ON, go to next step. If ACCS PID value indicates OFF, check operation of A/C demand 
switch. See appropriate A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING. 
Repair as necessary. If A/C demand switch is okay, repair short to PWR in A/C demand circuit to A/C 
cycling switch. 

21) Check ACCS Circuit For Short To PWR In Harness 
 
Turn ignition switch to OFF position. Disconnect PCM connector. Inspect connector for loose, damaged 
or corroded terminals. Repair as necessary. Turn ignition switch to ON position. Using a DVOM, 
measure voltage between chassis ground and ACCS circuit at PCM harness connector. See PCM 
CONNECTOR IDENTIFICATION. If voltage is less than one volt, replace PCM. If voltage is one volt 
or more, repair short to PWR in ACCS circuit. Verify symptom is no longer present. 

NOTE:

A break in step numbering sequence occurs at this point. Procedure skips 
from step 11) to step 19). No test procedures have been omitted.

NOTE:

For additional testing information, see DIAGNOSTIC AIDS.

NOTE:

Ensure both A/C and defroster were off during KOEO and KOER self-test. 
If either A/C or defroster were on during self-test, turn system off and 
repeat self-test.

NOTE:

A break in step numbering sequence occurs at this point. Procedure skips 

 

2003 Ford Pickup F150 

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

  

30) For Continuous Memory Only DTCs P0645 & P1460: Check A/C Clutch Relay Circuit For 
Intermittent Short To Ground 
DTC P1460 is set when an excessive current draw is detected when PCM grounds A/C clutch relay 
circuit, or voltage is not detected on A/C clutch relay circuit when PCM interrupts ground on A/C clutch 
relay circuit. Possible causes are: 

z

Open Or Shorted A/C clutch relay Circuit  

z

Faulty A/C clutch relay (Or CCRM)  

z

Open VPWR Circuit To A/C clutch relay  

z

Faulty PCM  

Ensure A/C is off. Turn ignition switch to ON position. Check A/C clutch relay circuit for short to ground 
(fault will be indicated by A/C clicking on) while performing the following:  

z

Shake, wiggle and bend WAC circuit between PCM and A/C clutch relay. See Fig. 339-Fig. 341 .  

z

Lightly tap on A/C clutch relay to simulate road shock.  

If no faults are found, go to next step. If any faults are found, isolate fault and repair as necessary. Start 
engine and allow to idle. Turn A/C on and wait 15 seconds. Turn A/C off and repeat QUICK TEST to 
verify repair. 

31) Check WAC Circuit For Intermittent Open Or Short To PWR 
 
Ensure ignition switch is turned to ON position. Using scan tool, access OUTPUT TEST MODE. See 
OUTPUT TEST MODE under ADDITIONAL SYSTEM FUNCTIONS. Command ALL OUTPUTS 
ON. Check A/C clutch relay circuit for open or short to PWR (fault will be indicated by A/C clicking off) 
while performing the following: 

z

Shake, wiggle and bend A/C clutch relay circuit between PCM and A/C clutch relay.  

z

Shake, wiggle and bend VPWR circuit to A/C clutch relay.  

z

Lightly tap on A/C clutch relay to simulate road shock.  

If no faults are found, check for intermittent faults. Go to TEST Z, step 1). If any faults are found, isolate 
fault and repair as necessary. Perform PCM RESET PROCEDURE under CLEARING CODES under 
SELF-DIAGNOSTIC SYSTEM. Start engine and allow to idle. Turn A/C on and wait 15 seconds. Turn 
A/C off and repeat QUICK TEST to verify repair. 

TEST KN: VARIABLE SPEED ELECTRIC COOLING FAN 

from step 21) to step 30). No test procedures have been omitted.

NOTE:

For additional testing information, see DIAGNOSTIC AIDS.

NOTE:

If vehicle is not equipped with A/C, A/C clutch relay circuit is not used and 
DTC P1460 can be ignored.

 

2003 Ford Pickup F150 

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

  

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

Variable speed electric cooling fan.  

z

Harness circuits: FCV, B+, VPWR, ground.  

z

Powertrain Control Module (PCM).  

Fig. 350: Identifying Variable Speed Fan Circuits & Connector Terminals (Crown Victoria, Grand 
Marquis & Town Car) 
Courtesy of FORD MOTOR CO. 

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