Ford F150 Pickup. Instruction - part 1458

z

Spark (EEC-Controlled)  

To prevent replacement of good components, be aware the following non-EEC related areas and components 
may be cause of concern:  

z

Fuel Quality & Quantity  

z

Ignition (General Condition)  

z

Engine Mechanical Components  

z

Starter & Battery Circuits  

Testing 

1) Check Passive Anti-Theft System (Securi-Lock) 
 
If vehicle does not have an anti-theft system, go to next step. If vehicle has an anti-theft system, it may be 
activated causing the no-start condition. Verify by observing anti-theft indicator light being illuminated 
on instrument panel, or a DTC P1260 may be present. If anti-theft system is not activated, go to next step. 
If anti-theft system is activated, see appropriate ANTI-THEFT SYSTEMS article in ACCESSORIES & 
EQUIPMENT for diagnosis and testing. 

2) Attempt To Crank Engine 
 
Ensure Inertia Fuel Shutoff (IFS) switch is closed (button pushed in). Attempt to start engine. If engine 
does not crank, check vehicle starting and charging systems. See appropriate STARTERS or 
GENERATORS & REGULATORS article in STARTING & CHARGING SYSTEMS. Repair as 
necessary and retest. If engine cranks, go to next step. 

3) Check For Intermittent No Start 
 
Attempt to start engine. If engine now starts, fault is intermittent. Go to TEST Z, step 2). If engine does 
not start, go to next step. 

4) Check VREF Voltage To TP Sensor 
 
Turn ignition switch to OFF position. Disconnect TP sensor. Turn ignition switch to ON position. Using a 
DVOM, measure voltage between circuits VREF and SIG RTN at TP sensor harness connector. See Fig. 
163-Fig. 166 . If voltage is 4-6 volts, turn ignition switch to OFF position, reconnect TP sensor connector 
and go to next step. If voltage is not 4-6 volts, turn ignition switch to OFF position and go to TEST C, 
step 1). 

 

2003 Ford Pickup F150 

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

  

Fig. 163: Identifying TP Sensor Circuits & Connector Terminals - Focus 2.0L (4V) & 2.3L, & 
Ranger 2.3L 
Courtesy of FORD MOTOR CO. 

 

2003 Ford Pickup F150 

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

  

Fig. 164: Identifying TP Sensor Circuit & Connector Terminals - LS & Thunderbird 
Courtesy of FORD MOTOR CO. 

Fig. 165: Identifying TP Sensor Circuits & Connector Terminals - ZX2 2.0L (4V) 
Courtesy of FORD MOTOR CO. 

 

2003 Ford Pickup F150 

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

  

Fig. 166: Identifying TP Sensor Circuits & Connector Terminals - All Others 
Courtesy of FORD MOTOR CO. 

5) Check Flash EPROM (FEPS) Circuit For Short To Power 
 
Using a DVOM, measure voltage between negative battery terminal and DLC terminal No. 13. See Fig. 
1. If voltage is more than 9 volts, repair FEPS circuit for a short to VPWR. If voltage is 9 volts or less on 
models with coil-on-plug, go to step 17). If voltage is 9 volts or less on all others, go to next step. 

6) Check RPM PID In PCM 
Turn ignition switch to OFF position. Using scan tool, access RPM PID from PID/DATA MONITOR & 
RECORD menu. Observe RPM PID on scan tool while cranking engine. If RPM PID does not indicate 
cranking speed, turn ignition switch to OFF position and go to TEST JD, step 1). If RPM PID value 
indicates cranking speed, check secondary ignition components (ignition coils, spark plugs and wires). 
See TEST JB, step 1). Repair as necessary. If secondary ignition on natural gas vehicles is okay, go to 

NOTE:

Ensure scan tool is connected to a reliable power source with ignition 
switch in START position, such as vehicle battery. Ensure vehicle battery 
is fully charged.

 

2003 Ford Pickup F150 

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