Ford F150 Pickup. Instruction — part 1535

Spark Tester (303-D037) to suspect coil(s). Check for spark at all cylinders while cranking engine. If
Blue-White spark is consistent between all cylinders, turn ignition switch to OFF position and go to next
step. If Blue-White spark is not consistent between all cylinders, check coil boots of missing cylinders.
Replace as necessary. If boots are okay, measure resistance of spark plug(s). If resistance is not 2-20
k/ohms, replace affected spark plug(s). Note cylinders with inconsistent spark and go to TEST JF, step 1).

18) Check Spark Plugs

Remove and inspect spark plugs for damage, wear, carbon deposits and proper plug gap. Adjust gap or
replace plugs as necessary. Perform DRIVE CYCLES. Ensure MISFIRE & FUEL MONITOR
PROCEDURES are performed to verify repair. If spark plugs are okay, go to next step.

19) Check Spark Plug Resistance

Measure resistance of spark plugs. If resistance is not 2-20 k/ohms, replace faulty spark plug. Perform
DRIVE CYCLES. Ensure MISFIRE & FUEL MONITOR PROCEDURES are performed to verify
repair. If spark plug resistance is within specification, proceed as follows:

z

If misfire is intermittent, go to TEST Z, step 1).

z

If directed here from SYMPTOMS in TROUBLE SHOOTING - NO CODES - CNG, FLEX-
FUEL & GASOLINE article, return to symptom test that directed you here.

z

If directed here from TEST HD, step 3), go to TEST HD, step 4).

z

If directed here from TEST A, step 6), return to TEST A, step 6).

20) DTC P0301-P0310: Misfire On Cylinders No. 1-10

If DTC P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308, P0309 or P0310 is present, go to
next step. If specified DTCs are not present, go to step 22).

21) Check For Spark At Cylinders Indicated By DTCs

Disable Inertia Fuel Shutoff (IFS) switch. Disconnect spark plug wire(s) from spark plug(s). Install Air
Gap Spark Tester (303-D037) to suspect spark plug wire. Check for spark from suspect spark plugs while
cranking engine. If Blue-White spark is present, turn ignition switch to OFF position and go to step 23). If
Blue-White spark is not present, measure resistance of spark plug wire to missing cylinder(s). Spark plug
wire resistance should be 7 k/ohms or less per foot. Repair as necessary. Perform DRIVE CYCLES.
Ensure MISFIRE & FUEL MONITOR PROCEDURES are performed to verify repair. If spark plug wire
resistance is within specification, go to TEST JE, step 1).

22) Check For Spark At All Spark Plugs

Disable Inertia Fuel Shutoff (IFS) switch. Disconnect spark plug wires from spark plugs. Install Air Gap
Spark Tester (303-D037) to suspect spark plug wire. Check for spark from each spark plug while
cranking engine. If Blue-White spark is consistent between all cylinders, turn ignition switch to OFF
position and go to next step. If Blue-White spark is inconsistent between cylinders, measure resistance of
spark plug wire to missing cylinder(s). Spark plug wire resistance should be 7 k/ohms or less per foot.
Repair as necessary. Perform DRIVE CYCLES. Ensure MISFIRE & FUEL MONITOR PROCEDURES

2003 Ford Pickup F150

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

are performed to verify repair. If spark plug wire resistance is within specification, go to TEST JE, step
1).

23) Check Spark Plugs

Remove and inspect spark plugs for damage, wear, carbon deposits and proper plug gap. Adjust spark
plug gap or replace spark plug(s) as necessary. Perform DRIVE CYCLES. Ensure MISFIRE & FUEL
MONITOR PROCEDURES are performed to verify repair. If spark plugs are okay, go to next step.

24) Check Spark Plug Resistance

Measure resistance of spark plugs. If resistance is not 2-20 k/ohms, replace faulty spark plug. Perform
DRIVE CYCLES. Ensure MISFIRE & FUEL MONITOR PROCEDURES are performed to verify
repair. If spark plug resistance is within specification, proceed as follows:

z

If concern is intermittent, go to TEST Z, step 1).

z

If directed here from SYMPTOMS in TROUBLE SHOOTING - NO CODES - CNG, FLEX-
FUEL & GASOLINE article, return to symptom test that directed you here.

z

If directed here from TEST HD, step 3), return to TEST HD, step 4).

z

If directed here from TEST A, step 6), return to TEST A, step 6).

TEST JD: CRANKSHAFT POSITION SENSOR

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

Crankshaft Position (CKP) Sensor

z

Wiring Harness Circuits (CKP+ & CKP-)

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

Fig. 287: Identifying CKP Sensor Circuits & Connector Terminals (Aviator, Explorer V8, Expedition,
Focus 2.0L 2V, LS V6, Mountaineer, Navigator & Ranger 3.0L)
Courtesy of FORD MOTOR CO.

2003 Ford Pickup F150

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

Fig. 288: Identifying CKP Sensor Circuits & Connector Terminals (Explorer 4.0L SOHC)
Courtesy of FORD MOTOR CO.

Fig. 289: Identifying CKP Sensor Circuits & Connector Terminals (Focus 2.0L 4V)
Courtesy of FORD MOTOR CO.

2003 Ford Pickup F150

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