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