Ford F150 Pickup. Instruction - 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