Ford F150 Pickup. Manual — part 1537

Fig. 294: Identifying Horizontal 6-Tower Coil Pack Wiring Harness Connector Terminals (Explorer
Sport & Explorer Sport Trac, Explorer & Mountaineer 4.0L SOHC With 104-Pin PCM, & Ranger 4.0L)
Courtesy of FORD MOTOR CO.

Fig. 295: Identifying Horizontal 6-Tower Coil Pack Wiring Harness Connector Terminals (Explorer &
Mountaineer 4.0L SOHC With 150-Pin PCM)
Courtesy of FORD MOTOR CO.

2003 Ford Pickup F150

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

Fig. 296: Identifying Series 5 Coil Pack Wiring Harness Connector Terminals (Econoline 4.2L, Mustang
3.8L, Pickup 4.2L, Ranger 3.0L, Sable & Taurus 3.0L 2V, & Windstar)
Courtesy of FORD MOTOR CO.

IGNITION COIL-TO-CYLINDER CORRELATION (COIL PACK)

NOTE:

Performing step 1) and comparing test results to IGNITION COIL-TO-CYLINDER
CORRELATION (COIL PACK) table can help determine which coil is not firing.

Application & Cylinder No.

Coil Driver

PCM Terminal No.

DTC

4-Cylinder

1

A

26

P0351

3

B

52

P0352

4

A

26

P0351

2

B

52

P0352

V6 (104-Pin PCM 4.0L SOHC)

1

A

26

P0351

4

B

52

P0352

2

C

78

P0353

5

A

26

P0351

3

B

52

P0352

6

C

78

P0353

V6 (150-Pin PCM 4.0L SOHC)

1

A

E31

P0351

2003 Ford Pickup F150

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

Testing

1) For KOER & Continuous Memory Only DTC P0351, P0352, P0353 & P0354: Determine Which
Cylinder Is Not Firing
Each ignition primary circuit is continuously monitored. The test fails when the PCM does not receive a
valid IDM pulse signal from the ignition module (integrated in PCM). Possible causes are:

z

Open or short in ignition START/RUN circuit.

z

Open coil driver circuit in harness.

z

Coil driver circuit shorted to ground.

z

Damaged coil.

z

Damaged PCM.

z

Coil driver circuit shorted to PWR.

Using information from TEST JB: SECONDARY IGNITION, or DTC and IGNITION COIL-TO-
CYLINDER CORRELATION (COIL PACK) table and illustrations, determine which coil is not firing
properly. Record cylinder, coil driver and PCM harness connector terminal number(s) and go to next step.

2) Check IGN START/RUN Voltage To Coil Pack

Disconnect suspect coil that was determined in step 1) . Turn ignition switch to ON position. Using a
DVOM, measure voltage between chassis ground and IGN START/RUN circuit at suspect coil harness
connector. See Fig. 293-Fig. 296 . If voltage is more than 10 volts, go to step 5). If voltage is 10 volts or
less, fault is in IGN START/RUN circuit. Check condition of related fuse/fuse links. If fuse/fuse links are
blown, check for short to ground in IGN START/RUN circuit. Repair as necessary. If fuse/fuse links are
okay, repair open in IGN START/RUN circuit.

5) Check Functionality Of Suspect Coil Driver (CD) Circuit

Turn ignition switch to OFF position. Connect a test light between IGN START/RUN circuit and suspect
CD circuit at coil harness connector. Refer to IGNITION COIL-TO-CYLINDER CORRELATION
(COIL PACK) table to determine faulty driver circuit. Disable Inertia Fuel Shutoff (IFS) switch.
Observe test light while cranking engine. If test light blinks consistently, go to step 12). If test light does
not blink consistently, go to next step.

4

B

E23

P0352

2

C

E13

P0353

5

A

E31

P0351

3

B

E23

P0352

6

C

E13

P0353

NOTE:

For additional testing information, see DIAGNOSTIC AIDS.

NOTE:

A break in step numbering sequence occurs at this point. Procedure skips
from step 2) to step 5). No test procedures have been omitted.

2003 Ford Pickup F150

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

6) Check Suspect CD Circuit For Open In Harness

Turn ignition switch to OFF position. Disconnect PCM connector. Using a DVOM, measure resistance of
suspect CD circuit between PCM harness connector and appropriate coil harness connector. See PCM
CONNECTOR IDENTIFICATION and Fig. 293-Fig. 296 . If resistance is less than 5 ohms, go to next
step. If resistance is 5 ohms or more, repair open in appropriate CD circuit.

7) Check Suspect CD Circuit For Short To VPWR In Harness

Turn ignition switch to ON position. Using a DVOM, measure voltage between chassis ground and
suspect CD circuit at PCM harness connector. If voltage is less than one volt, go to next step. If voltage is
one volt or more, turn ignition switch to OFF position and repair short to VPWR in affected CD circuit.

8) Check Suspect CD Circuit For Short To Ground In Harness

Turn ignition switch to OFF position. Disconnect scan tool from DLC. Using a DVOM, measure
resistance of suspect CD circuit between chassis ground and PCM harness connector. See PCM
CONNECTOR IDENTIFICATION and Fig. 293-Fig. 296 . If resistance is more than 10 k/ohms,
replace PCM. Perform QUICK TEST procedures to ensure DTCs are no longer present. If symptom or
DTC is still present, go to step 11) to check for damaged coil. If resistance is 10 k/ohms or less, repair
short to ground in affected CD circuit. Perform QUICK TEST procedures to ensure DTCs are no longer
present. If symptom or DTC is still present, go to step 11) to check for damaged coil.

11) Check Suspect Coil For Damage

Disable Inertia Fuel Shutoff (IFS) switch. Disconnect spark plug wire from suspect coil tower. Refer to

IGNITION COIL-TO-CYLINDER CORRELATION (COIL PACK)

table to determine suspect coil.

Connect Air Gap Spark Tester (303-D037) in series between suspect coil tower and spark plug wire.
Observe spark tester while cranking engine. If Blue-White spark is present, turn ignition switch to OFF
position and go to step TEST Z, step 1). If Blue-White spark is not present, replace coil pack.

12) Check Coil Secondary

Disable Inertia Fuel Shutoff (IFS) switch. Reconnect coil harness connector. Disconnect spark plug wire
from suspect coil tower. Refer to IGNITION COIL-TO-CYLINDER CORRELATION (COIL
PACK) table to determine suspect coil. Connect Air Gap Spark Tester (303-D037) in series between
suspect coil tower and spark plug wire. Observe spark tester while cranking engine. If Blue-White spark
is present, turn ignition switch to OFF position and go to step TEST Z, step 1). If Blue-White spark is not
present, replace coil pack.

TEST JF: INTEGRATED IGNITION COIL ON PLUG FAILURE

NOTE:

A break in step numbering sequence occurs at this point. Procedure skips
from step 8) to step 11). No test procedures have been omitted.

NOTE:

After each service or repair procedure has been completed, reconnect all

2003 Ford Pickup F150

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