Content .. 1469 1470 1471 1472 ..

Ford F150 Pickup. Instruction - part 1471

11) For KOEO & KOER Only DTC P0190: Check VREF Circuit To FRP Sensor
DTC P0190 indicates VREF voltage from PCM dropped below minimum calibrated voltage during
Comprehensive Component Monitor (CCM). Possible causes for this fault are:

VREF Open Circuit In Harness

VREF Open Circuit In Sensor

VREF Open Circuit In PCM

Disconnect FRP sensor connector. Turn ignition switch to ON position. Using a DVOM, measure voltage
between VREF and SIG RTN circuits at FRP sensor harness connector. See Fig. 186 or Fig. 187 . If
voltage is 4-6 volts, go to step 13) (gasoline engines). If voltage is 4-6 volts, go to step 14) (natural gas
engines). If voltage is not 4-6 volts, go to next step.

12) Check FRP, SIG RTN & VREF Circuits For Open In Harness

Turn ignition switch to OFF position. Disconnect PCM connector(s). Inspect connector for loose,
damaged or corroded terminals. Repair as necessary. Using a DVOM, measure resistance of FRP, SIG
RTN and VREF circuits between FRP sensor harness connector and PCM harness connector. See PCM
CONNECTOR IDENTIFICATION and Fig. 186 or Fig. 187 . If all resistance measurements are less
than 5 ohms, go to next step (gasoline engines). If all resistance measurements are less than 5 ohms, go to
step 14) (natural gas engines). If any resistance measurement is 5 ohms or more, repair open in affected
circuit.

13) Check FRP Voltage PID During Fuel Rail Pressure Relief (Gasoline)

Connect PCM. Connect FRP sensor. Disable fuel delivery system (remove fuel pump fuse). Turn ignition
switch to ON position. Access the FRP V PID while cranking the engine to relieve the fuel rail pressure.
The FRP voltage will decrease as the fuel rail pressure drops and will stabilize when the fuel rail pressure
reaches atmospheric pressure. Note the FRP voltage after it stabilizes at lowest level. If FRP V voltage
does not stabilize between 0.3 and 0.7 V, turn ignition switch to OFF position. Replace fuel rail pressure
sensor and enable fuel system. If FRP V voltage stabilizes between 0.3 and 0.7 V, proceed as follows:

If only Continuous Memory DTC P0190 is present, go to step 16).

If DTC P0192 is present, replace PCM.

If DTC P0193 is present, go to step 15).

14) Check FRP Voltage PID During Fuel Rail Pressure Relief (Natural Gas)

Connect PCM. Connect FRP sensor. Access FRP V PID. Relieve fuel pressure. See FUEL SYSTEM
PRESSURE RELEASE under FUEL SYSTEMS in SYSTEM & COMPONENT TESTING - CNG.
Crank engine. If FRP V voltage does not stabilize between 0.4 and 0.6 V, turn ignition switch to OFF
position. Replace fuel rail pressure sensor and enable fuel system. If FRP V voltage stabilizes between
0.4 and 0.6 V, proceed as follows:

If only Continuous Memory DTC P0190 is present, go to step 16).

If DTC P0192 is present, replace PCM.

leaks and verify fuel level.

2003 Ford Pickup F150

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

If DTC P0193 is present, go to step 15).

15) Check FRP Circuit For Short To VREF Or VPWR In Harness

Turn ignition switch to OFF position. Disconnect PCM connector(s). Inspect connector for loose,
damaged or corroded terminals. Repair as necessary. Using a DVOM, measure between FRP and VREF,
and VPWR circuits at PCM harness connector. See PCM CONNECTOR IDENTIFICATION and

Fig.

186

or Fig. 187 . See PCM VPWR CIRCUIT TERMINAL IDENTIFICATION table. If both

resistance measurements are more than 10 k/ohms, replace PCM. If either resistance measurement is 10
k/ohms or less, repair short in affected circuit.

PCM VPWR CIRCUIT TERMINAL IDENTIFICATION

16) For Continuous Memory Only DTC P0190, P0192 & P0193: Check For Intermittent Fault
Reconnect FRP sensor connector. Turn ignition switch to ON position. Using scan tool, access FRP V
PID from PID/DATA MONITOR & RECORD menu. Observe FRP V PID reading for fault while
tapping on FRP sensor. Wiggle and bend wiring harness and connector between sensor and PCM. Fault
will be indicated by a sudden change in FRP V PID voltage. If fault is indicated, isolate and repair as
necessary. If fault is not indicated, symptom is intermittent and cannot be located at this time. Go to
TEST Z, step 1) for additional test procedures.

17) For KOEO, KOER & Continuous Memory DTC P0191, & For Continuous Memory Only
P1168 Or P1169 (NGV Only): Check Fuel Pressure
If DTC P0230, P0231 and/or P0232 are present with DTC P0191, service DTC P0230, P0231 or P0232
before DTC P0191. See DIAGNOSTIC TROUBLE CODE DEFINITIONS. DTC P0191, P1168 or
P1169 indicate fuel pressure fell below minimum or exceeded maximum calibrated limit for a calibrated
period of time during Comprehensive Component Monitor (CCM). Possible causes for this fault are:

High Fuel Pressure

Low Fuel Pressure

Excessive Resistance In Circuit

Faulty FRP Sensor

Low Or No Fuel

Turn ignition switch to ON position. Ensure vehicle has at least 1/8 tank of fuel. Turn ignition switch to

Application

PCM Terminal No.

Models With 104-Pin PCM

71 & 97

Models With 122-Pin PCM

B34, B46 & E9

Models With 150-Pin PCM

A32 & A33, Or B32 & B33

NOTE:

For additional testing information, see DIAGNOSTIC AIDS.

NOTE:

For additional testing information, see DIAGNOSTIC AIDS.

NOTE:

On CNG models, if vehicle is a no-start, go to TEST HB, step 1).

2003 Ford Pickup F150

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

OFF position. Release fuel pressure. See FUEL SYSTEM PRESSURE RELEASE procedure under
FUEL SYSTEMS in appropriate REMOVAL & INSTALLATION article. Connect pressure gauge to
Schrader valve on fuel rail. Turn ignition switch to ON position, with engine OFF. Check fuel pressure.
Fuel pressure should be within specification. See Fig. 167. If fuel pressure is within specification, go to
next step. If fuel pressure is not within specification, go to TEST HB, step 1) (natural gas vehicles), or
TEST HC, step 1) (gasoline vehicles).

18) Check Fuel Pressure With FRP PID

Connect scan tool to Data Link Connector (DLC). Ensure fuel pressure gauge is still connected. Turn
ignition switch to ON position. Using scan tool, access FRP PID from PID/DATA MONITOR &
RECORD menu. If FRP PID value is not within 10 psi of fuel pressure gauge measurement, go to next
step (natural gas vehicles), or step 20) (gasoline vehicles). If FRP PID value is within 10 psi of fuel
pressure gauge measurement, proceed as follows:

If DTC P1168 or DTC P1169 are present, perform KEEP ALIVE RANDOM ACCESS
MEMORY RESET PROCEDURE under CLEARING CODES under SELF-DIAGNOSTIC
SYSTEM. Road test vehicle 3-5 minutes at a steady speed. Stop vehicle and check for Continuous
Memory DTCs. If DTC P1168 or DTC P1169 are still present, go to next step.

If DTC P0191 is present in Continuous Memory, go to step 15).

If any other DTC is present, repeat QUICK TEST.

19) Check Fuel Rail Solenoid Operation

Turn ignition switch to ON position. Using scan tool, access OUTPUT TEST MODE. See OUTPUT
TEST MODE under ADDITIONAL SYSTEM FUNCTIONS. While observing fuel rail solenoid, cycle
output ON and OFF several times. If fuel rail solenoid clicking can be heard or felt, turn ignition switch
to OFF position, exit OUTPUT TEST MODE, reconnect solenoid and go to next step. If fuel rail solenoid
is not heard or felt clicking, turn ignition switch to OFF position and go to step 23).

20) Check VREF Voltage To FRP Sensor

Disconnect FRP sensor connector. Turn ignition switch to ON position. Using a DVOM, measure voltage
between VREF and SIG RTN circuits at FRP sensor harness connector. See Fig. 186 or Fig. 187 . If
voltage is 4-6 volts, go to next step. If voltage is not 4-6 volts, go to TEST C, step 1).

21) Check FRP Circuit For Excessive Resistance

Turn ignition switch to OFF position. Disconnect PCM connector(s). Inspect connector for loose,
damaged or corroded terminals. Repair as necessary. Using a DVOM, measure resistance of FRP, SIG
RTN and VREF circuits between FRP sensor harness connector and PCM harness connector. See PCM
CONNECTOR IDENTIFICATION and Fig. 186 or Fig. 187 . If all resistance measurements are less
than 5 ohms, go to next step. If any resistance measurement is 5 ohms or more, repair open in affected
circuit.

22) Monitor FRP V PID With Scan Tool

2003 Ford Pickup F150

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

Turn ignition switch to ON position. Using scan tool, access FRP V PID from PID/DATA MONITOR &
RECORD menu. If FRP V PID voltage is less than .2 volt (natural gas vehicles), or more than 4.8 volts
(gasoline vehicles), replace FRP sensor. If FRP V PID voltage is not as specified, replace PCM.

23) Check FSV PWR Voltage To Fuel Rail Solenoid Shut-Off Valve Harness Connector
Disconnect fuel rail solenoid connector. Turn ignition switch to ON position. Using scan tool, access
OUTPUT TEST MODE. See OUTPUT TEST MODE under ADDITIONAL SYSTEM FUNCTIONS.
Select outputs ALL ON. Using a DVOM, measure voltage on FSV VPWR circuit between negative
battery terminal and fuel rail solenoid harness connector. See WIRING DIAGRAMS. If voltage is more
than 10.5 volts, go to next step. If voltage is 10.5 volts or less, repair open in FSV VPWR circuit.

24) Check Ground Circuit For Open In Harness

Using a DVOM, measure resistance of ground circuit between negative battery terminal and fuel rail
solenoid harness connector. If resistance is less than 5 ohms, replace fuel rail solenoid shut-off valve. If
resistance is 5 ohms or more, repair open in ground circuit.

25) Check VREF Voltage To FRP Sensor

Turn ignition switch to OFF Position. Disconnect FRP sensor connector. Turn ignition switch to ON
position. Using a DVOM, measure voltage between VREF and SIG RTN circuits at FRP sensor harness
connector. 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).

26) Check FRP Circuit For Short To SIG RTN, VREF Or PWR GND In Harness

Turn ignition switch to OFF position. Disconnect scan tool from Data Link Connector (DLC). Disconnect
PCM connector(s). Inspect connector for loose, damaged or corroded terminals. Repair as necessary.
Using a DVOM, measure resistance between FRP circuit, SIG RTN and VREF circuits at PCM harness
connector (both VREF circuits on 150-pin PCM), and negative battery terminal. See PCM
CONNECTOR IDENTIFICATION and Fig. 186 or Fig. 187 . See WIRING DIAGRAMS. If all
resistance measurements are more than 10 k/ohms, replace PCM. If any resistance measurement is 10
k/ohms or less, repair short in affected circuit.

NOTE:

When ALL ON is selected in OUTPUT TEST MODE, voltage measurement
must be made within 7 seconds of activating test mode.

2003 Ford Pickup F150

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

Content .. 1469 1470 1471 1472 ..