Test Procedure
WARNING: This page is about a different car, the 2007 Mercury Mariner and 2007 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
- JF1 CHECK FOR THE PRESENCE OF PCM DIAGNOSTIC TROUBLE CODES (DTCS) P0351, P0352, P0353, AND P0354 TOGETHER NOTE: DTCs P0351, P0352, P0353 and P0354 together indicate that all 4 ignition coils lost IGN START/RUN voltage while the PCM sustained VPWR.
Possible causes:
- IGN START/RUN circuit open
- ISP-R short to PWR
- Are PCM continuous DTCs P0351, P0352, P0353, and P0354 present together during the self-test?
Yes No GO to JF2. GO to JF3. - JF2 CHECK THE IGNITION SWITCH RUN POSITION CIRCUIT FOR A SHORT TO VPWR IN THE HARNESS
- Check the condition of the IGN START/RUN circuit related fuses.
- Key in OFF position.
- PCM connector disconnected.
- Measure the voltage between:
( + ) PCM Connector, Harness Side ( - ) Vehicle Battery ISP-R Negative terminal - Is the voltage less than 1 V?
Yes No GO to JF11. CHECK for a damaged ignition switch.
REFER to the Wiring Diagrams Cell 149 Component Testing.
If the ignition switch is OK, REPAIR the short to PWR circuit in the harness. - JF3 DETERMINE WHICH COIL IS NOT FIRING PROPERLY NOTE: Electronic ignition engine timing is entirely controlled by the PCM. Electronic ignition timing is NOT adjustable. Do not attempt to check base timing. You will receive false readings.
- Determine which coil is not firing properly using the information from Pinpoint Test JB or a DTC and the table at the beginning of this pinpoint test.
- Record the suspect cylinder, coil, and PCM pin number from the table.
- Have the suspect cylinder number, coil driver, and PCM pin number been recorded?
Yes No GO to JF4. REPEAT the test step to obtain the required information. - JF4 CHECK THE FUNCTIONALITY OF THE SUSPECT COIL DRIVER CIRCUIT
- Suspect coil connector disconnected.
- PCM connector connected.
- Connect a non-powered test lamp between the IGN START/RUN and suspect coil driver, harness side.
- Crank the engine using the engine cranking diagnostic mode. Refer toDIAGNOSTIC MODES .
- Observe the test lamp while cranking the engine.
- Is the test lamp blinking consistently?
Yes No GO to JF5. GO to JF6. - JF5 CHECK THE FUNCTIONALITY OF THE SUSPECT COIL
- Key in OFF position.
- Carry out a visual inspection. Closely inspect the coil case and boot for carbon tracking, cracks and torn or improperly installed boots.
- Remove the suspect COP from the spark plug.
- Connect air gap spark tester 303-D037 (D81P-6666-A) or equivalent to the suspect coil.
- Suspect coil connector connected.
- Crank the engine using the engine cranking diagnostic mode. Refer toDIAGNOSTIC MODES .
- Observe the spark tester while cranking the engine.
- Is a bluish-white spark present?
Yes No refer to PINPOINT TEST Z . INSTALL a new coil as necessary.
INSPECT the spark plug, INSTALL a new spark plug as necessary.
CLEAR the DTCs. REPEAT the self-test. - JF6 CHECK IGN START/RUN VOLTAGE TO SUSPECT COIL
- Measure the voltage between:
( + ) COP Connector, Harness Side ( - ) Vehicle Battery IGN START/RUN - Pin 2 Negative terminal - Is the voltage greater than 10.5 V?
Yes No GO to JF7. REPAIR the circuit.
CLEAR the DTCs. REPEAT the self-test. - Measure the voltage between:
- JF7 CHECK THE SUSPECT COIL DRIVER CIRCUIT FOR AN OPEN IN THE HARNESS
- Key in OFF position.
- PCM connector disconnected.
- Measure the resistance between:
( + ) PCM Connector, Harness Side ( - ) COP Connector, Harness Side Suspect coil driver COP - Pin 1 - Is the resistance less than 5 ohms?
Yes No GO to JF8. REPAIR the circuit.
CLEAR the DTCs. REPEAT the self-test. - JF8 CHECK THE SUSPECT COIL DRIVER CIRCUIT FOR A SHORT TO VPWR IN THE HARNESS
- Key ON, engine OFF.
- Measure the voltage between:
( + ) PCM Connector, Harness Side ( - ) Vehicle Battery Suspect coil driver Negative terminal - Is the voltage less than 1 V?
Yes No GO to JF9. REPAIR the circuit.
CLEAR the DTCs. REPEAT the self-test. - JF9 CHECK THE SUSPECT COIL DRIVER CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS
- Key in OFF position.
- Measure the resistance between:
( + ) PCM Connector, Harness Side ( - ) Vehicle Battery Suspect coil driver Negative terminal - Is the resistance greater than 10K ohms?
Yes No INSTALL a new PCM.
REFER toFLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) .
If the concern or DTC is still present,
GO to JF10.REPAIR the circuit. If the concern or DTC is still present,
GO to JF10. - JF10 CHECK THE SUSPECT COIL FOR DAMAGE
- Carry out a visual inspection. Closely inspect the coil case and boot for carbon tracking, cracks, and torn or improperly installed boots.
- Remove the suspect COP from the spark plug.
- Connect air gap spark tester 303-D037 (D81P-6666-A) or equivalent to the suspect coil.
- Suspect coil connector connected.
- Crank the engine using the engine cranking diagnostic mode. Refer toDIAGNOSTIC MODES .
- Observe the spark tester while cranking the engine.
- Is a bluish-white spark present?
Yes No INSPECT the spark plug. INSTALL a new spark plug as necessary. INSTALL a new COP.
INSPECT the spark plug. INSTALL a new spark plug as necessary.
CLEAR the DTCs. REPEAT the self-test. - JF11 CHECK FOR CORRECT PCM OPERATION
- Disconnect all the PCM connectors.
- Visually inspect for:
- pushed out pins
- corrosion
- Connect all the PCM connectors and make sure they seat correctly.
- Carry out the PCM self-test and verify the concern is still present.
- Is the concern still present?
Yes No INSTALL a new PCM. REFER toFLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) . The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.