Ford F150 Pickup. Instruction - 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