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 suspect CD
circuit between PCM harness connector and appropriate coil-on-plug harness connector. Refer to
IGNITION COIL-TO-CYLINDER CORRELATION (COIL-ON-PLUG) table to determine PCM
terminal number. See Fig. 297 or Fig. 298 . If resistance is less than 5 ohms, go to next step. If resistance
is 5 ohms or more, repair open in CD circuit.
6) 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 terminal. Refer to IGNITION COIL-TO-CYLINDER
CORRELATION (COIL-ON-PLUG) table to determine PCM terminal number. If voltage is less than
one volt, go to next step. If voltage is one volt or more, repair CD circuit for short to VPWR.
7) 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. Refer to
IGNITION COIL-TO-CYLINDER CORRELATION (COIL-ON-PLUG) table to determine PCM
terminal number. If resistance is more than 10 k/ohms, replace PCM. If symptom or DTC still exists after
replacing PCM, go to next step to check for damaged coil. If resistance is 10 k/ohms or less, repair short
to ground in CD circuit. If symptom or DTC still exists after repair is complete, go to next step to check
for damaged coil.
8) Check Suspect Coil For Damage
Remove suspect coil from spark plug. Refer to IGNITION COIL-TO-CYLINDER CORRELATION
(COIL-ON-PLUG) table to determine suspect coil. Install Air Gap Spark Tester (303-D037) to suspect
coil. Reconnect coil harness connector. Observe spark tester while cranking engine. If spark is not
present, replace coil. Inspect spark plug and replace as necessary. If spark is present, check spark plug.
Replace as necessary and retest. If spark plug is okay, no fault is present at this time. Go to TEST Z, step
1).
TEST JH: TACHOMETER OUTPUT FAILURE
Diagnostic Aids
Perform this test when instructed to or if directed by other test procedures. This test is used to diagnose the
PCM.
Testing
NOTE:
Applies only to models with Clean Tachometer Output (CTO) circuit from
Powertrain Control Module (PCM) connector terminal No. 48. 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.
2003 Ford Pickup F150
2003 ENGINE PERFORMANCE Self-Diagnostics - CNG, Flex-Fuel & Gasoline