Ford F150 Pickup. Manual — part 1486

If ACP V PID voltage is 4.9 volts or more, replace PCM. Start engine and turn A/C on for 15 seconds.
Turn A/C off and repeat QUICK TEST. If ACP V PID voltage is less than 4.9 volts, replace ACP sensor.
Start engine and turn A/C on for 15 seconds. Turn A/C off and repeat QUICK TEST.

10) For KOEO, KOER & Continuous Memory DTC P1462: Check ACP V PID
This DTC indicates PCM has detected low voltage in ACP circuit. Possible causes for this fault are:

z

ACP Circuit Open, Or Shorted To GND Or SIG RTN

z

VREF Circuit Open

z

Faulty Powertrain Control Module (PCM)

z

Faulty ACP Sensor

Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition
switch to ON position. Using scan tool, access ACP V PID from PID/DATA MONITOR & RECORD
menu. If ACP V PID voltage is .15 volt or less, go to next step. If ACP V PID voltage is more than .15
volt, fault is unable to be duplicated at this time. Go to step 18).

11) Check Voltage Between VREF & SIG RTN To ACP Sensor

Turn ignition switch to OFF position. Disconnect ACP sensor connector. Turn ignition switch to ON
position. Using a DVOM, measure voltage between SIG RTN and VREF circuits at ACP sensor harness
connector. See Fig. 211. If voltage is 4-6 volts, go to next step. If voltage is not 4-6 volts, VREF is out of
range. Turn ignition switch to OFF position and go to TEST C, step 1).

12) Induce Opposite ACP Signal

Turn ignition switch to OFF position. Connect a jumper wire between ACP and VREF circuits at ACP
sensor harness connector. See Fig. 211. Turn ignition switch to ON position. Using scan tool, access ACP
V PID from PID/DATA MONITOR & RECORD menu.

If ACP V PID voltage is 4 volts or less, go to next step. If ACP V PID voltage is more than 4 volts,
replace ACP sensor. Refer to appropriate MANUAL or AUTOMATIC A/C-HEATER SYSTEMS article
in AIR CONDITIONING & HEATING. Start engine and turn A/C on for 15 seconds. Turn A/C off and
repeat QUICK TEST.

13) Check ACP Circuit For Short To PWR GND Or SIG RTN

Turn ignition switch to OFF position. Disconnect scan tool from DLC. Disconnect PCM connector(s).

NOTE:

A break in step numbering sequence occurs at this point. Procedure skips
from step 7) to step 10). No test procedures have been omitted.

NOTE:

For additional testing information, see DIAGNOSTIC AIDS.

NOTE:

If a scan tool communication concern exists, remove jumper wire and go
to next step.

2003 Ford Pickup F150

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

Using a DVOM, measure resistance between ACP circuit, and SIG RTN circuit at ACP sensor harness
connector, and negative battery terminal. See Fig. 211. If both resistance measurements are more than 10
k/ohms, go to next step. If either resistance measurement is 10 k/ohms or less, repair short to ground in
affected circuit. Start engine and turn A/C on for 15 seconds. Turn A/C off and repeat QUICK TEST.

14) Check ACP Circuit For Open In Harness

Using a DVOM, measure resistance of ACP circuit between PCM harness connector and ACP sensor
harness connector. See Fig. 211. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms
or more, repair open in ACP circuit. Start engine and turn A/C on for 15 seconds. Turn A/C off and repeat
QUICK TEST.

15) Check For The A/C Clutch To Engage

Turn ignition switch to OFF position. Reconnect ACP sensor. Turn ignition switch to ON position. Turn
A/C switch to ON position while listening for A/C clutch engagement. If A/C clutch engages when A/C
is turned on, replace PCM. Start engine and turn A/C on for 15 seconds. Turn A/C off and repeat QUICK
TEST. If A/C clutch does not engage when A/C is turned on, go to next step.

16) Check A/C System Refrigerant Charge

Reconnect all components. Connect A/C manifold gauge set and check if A/C system has correct
refrigerant charge. Service A/C system as necessary. For additional information, see appropriate
MANUAL or AUTOMATIC A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING.
Start engine and turn A/C on for 15 seconds. Turn A/C off and repeat QUICK TEST. If A/C system has
correct refrigerant charge, replace PCM. Start engine and turn A/C on for 15 seconds. Turn A/C off and
repeat QUICK TEST.

18) Check For Intermittent ACP Circuit Fault

Turn ignition switch to ON position. Using scan tool, access ACP V PID from PID/DATA MONITOR &
RECORD menu. While observing ACP V PID, lightly tap on ACP sensor and wiggle and bend ACP, SIG
RTN and VREF circuits between ACP sensor and PCM to simulate road shock. A fault is indicated by a
sudden change of ACP V PID voltage. If fault is indicated, isolate and repair as necessary. Start engine
and turn A/C on for 15 seconds. Turn A/C off and repeat QUICK TEST. If no faults are indicated, fault
is unable to be duplicated at this time. Go to TEST Z, step 1).

20) For Continuous Memory Only DTC P1463: Verify A/C Clutch Can Disengage

NOTE:

A break in step numbering sequence occurs at this point. Procedure skips
from step 16) to step 18). No test procedures have been omitted.

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

This DTC indicates PCM has detected that ACP sensor did not detect sufficient change in A/C system
pressure when A/C switch was turned to ON position. Possible causes for this fault are:

z

A/C System Mechanical Malfunction

z

Open ACP Or VREF Circuit

z

Faulty ACP Sensor

z

A/C System Electrical Malfunction (Non-EEC Related)

z

A/C Clutch Continuous Engagement

Ensure A/C and defroster are off. Start engine and allow to idle. Verify A/C clutch is disengaged. If A/C
clutch is disengaged, go to next step. If A/C clutch is not disengaged, diagnose by symptom. See
CLIMATE CONTROL (LACK OF A/C COOLING, A/C ALWAYS ON OR A/C INOPERATIVE)
under SYMPTOMS in TROUBLE SHOOTING - NO CODES - CNG, FLEX-FUEL & GASOLINE
article. Repair as necessary.

21) Check For Voltage & Ground To A/C Clutch
Turn ignition switch to OFF position. Disconnect A/C cycling switch. Connect a jumper wire between
A/C cycling switch harness connector terminals. Disconnect A/C clutch. Connect non-powered test light
between power and ground terminals at A/C clutch harness connector. Start engine and allow to idle.
Turn A/C switch on. Monitor test light for 15 seconds. If test light comes on or A/C clutch can be heard
clicking, go to next step. If test light does not come on or A/C clutch cannot be heard clicking, see
appropriate MANUAL or AUTOMATIC A/C-HEATER SYSTEMS article in AIR CONDITIONING &
HEATING.

22) Check If A Sufficient A/C Pressure Change Can Be Detected By The ACP PID

Start engine and allow to idle. Ensure A/C is off. Using scan tool, access ACP V PID from PID/DATA
MONITOR & RECORD menu. Note A/C V PID voltage reading. Monitor ACP V PID value and turn
A/C on. Note ACP V PID voltage reading within 5 seconds of A/C clutch engagement and compare
measurement with ACP V PID reading noted previously. If A/C clutch does not engage, or if ACP V PID
voltage change is .3 volt or less, go to next step. If ACP V PID voltage change is more than .3 volt, ACP
sensor and PCM can detect a sufficient change in A/C pressure. If directed here by DTC P1463, diagnose
by symptom. See SYMPTOMS in TROUBLE SHOOTING - NO CODES - CNG, FLEX-FUEL &
GASOLINE article. Repair as necessary. For all others, see appropriate MANUAL or AUTOMATIC
A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING. Check A/C system for proper
operation and repair as necessary. After servicing A/C system, start engine and turn A/C on for 15
seconds. Turn A/C off and repeat QUICK TEST.

23) Check A/C System Pressure & Pressure Change

Turn ignition switch to OFF position. Reconnect all components. Connect A/C manifold gauge set. Start
engine and allow to idle. With A/C off, note high pressure measurement. Turn A/C on. Wait 5 seconds

NOTE:

If voltage and ground to A/C clutch have already been confirmed okay with
a non-powered test light in TROUBLE SHOOTING - NO CODES - CNG,
FLEX-FUEL & GASOLINE article, or if A/C clutch can be heard clicking on
when A/C is turned on, go to step 22).

2003 Ford Pickup F150

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

and note high pressure measurement again. Turn A/C off. If high pressure measurement changes more
than 30 psi (207 kPa) within 5 seconds of clutch engagement, go to next step. If high pressure
measurement does not change more than 30 psi (207 kPa) within 5 seconds of clutch engagement, A/C
system pressure did not change as expected. Service A/C system as necessary. See appropriate MANUAL
or AUTOMATIC A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING. After
servicing A/C system, start engine and turn A/C on for 15 seconds. Turn A/C off and repeat QUICK
TEST.

24) Check Voltage Between VREF & SIG RTN Circuit To ACP Sensor

Turn ignition switch to OFF position. Disconnect ACP sensor connector. Turn ignition switch to ON
position. Using a DVOM, measure voltage between SIG RTN and VREF circuits at ACP sensor harness
connector. See Fig. 211. If voltage is 4-6 volts, go to next step. If voltage is not 4-6 volts, VREF is out of
range. Go to TEST C, step 1).

25) Check ACP Circuit For Open In Sensor

Turn ignition switch to OFF position. Ensure ACP sensor harness connector is disconnected. Disconnect
PCM connector(s). Using a DVOM, measure resistance of ACP circuit between PCM harness connector
and ACP sensor harness connector. See Fig. 211. If resistance is less than 5 ohms, replace ACP sensor.
Start engine and turn A/C on for 15 seconds. Turn A/C off and repeat QUICK TEST. If resistance is 5
ohms or more, repair open in ACP circuit. Start engine and turn A/C on for 15 seconds. Turn A/C off and
repeat QUICK TEST.

TEST DT: POWER STEERING PRESSURE SENSOR

Diagnostic Aids

Perform this test when directed by QUICK TEST or other test procedures. This test is intended to diagnose the
following:

z

PSP Sensor

z

Wiring Harness Circuits (PSP, SIG RTN & VREF)

z

Powertrain Control Module (PCM)

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 and DTCs are no longer present.

2003 Ford Pickup F150

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