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Home >> Mercury >> 2006 >> Milan Base, 2.3 Z, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Pinpoint Test HY: Generator/Regulator System Through Pinpoint Test KD: Electric Exhaust Gas RECIRCULATION (EEGR) System - (Except Diesel & Hybrid) >> Pinpoint Test JC: Secondary Ignition (Coil Pack) >> Test Procedure
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Test Procedure

  1. JC1 CHECK FOR DTCS 

    Are DTCs P0300, P0301, P0302, P0303, P0304, P0305, P0306 or P050B present? 

    Yes No
    For DTCs P0301, P0302, P0303, P0304, P0305 or P0306, GO to  JC13.
    For DTC P0300, GO to  JC2.
    For DTC P050B, GO to  JC18.    		 For all other DTCs, GO to DIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONS .
  2. JC2 VISUAL INSPECTION OF THE IGNITION SYSTEM 
    • Visually inspect the engine compartment to make sure all coils and spark plug wires are properly and securely connected.
    • Examine all wiring harnesses and connectors for damaged, burned or overheated insulation and loose or broken conditions.
    • Make sure the vehicle battery is in good condition and all accessories are turned off.

    Is a concern present? 

    Yes No
    REPAIR as necessary. For a coil pack using an engine analyzer, GO to  JC3.
    CLEAR the DTCs. REPEAT the self-test. For a coil pack not using an engine analyzer, GO to  JC12.
  3. JC3 CONNECT THE ENGINE ANALYZER 
    • Obtain an engine analyzer to diagnose concerns in the secondary side of the ignition system.

    Is the engine analyzer connected? 

    Yes No
    GO to  JC4. REPEAT Step  JC2.
  4. JC4 CHECK FOR THE IGNITION PATTERN 
    • Observe the pattern on a scope while cranking the engine.
      Fig 1: Ignition Firing Pattern (No Spark)
      G04587237Courtesy of FORD MOTOR CO.

    Is the pattern flat, which indicates no spark on all cylinders? 

    Yes No
    An IGN/START/RUN circuit concern. CHECK the condition of the related fuses/fuse links. If OK, REPAIR the open circuit. If the fuse/fuse link is damaged, CHECK the IGN START/RUN circuit for a short to ground. REPAIR as necessary.
    CLEAR the DTCs. REPEAT the self-test.    		 GO to  JC5.
  5. JC5 CHECK FOR A NORMAL IGNITION PATTERN 
    NOTE: Spark plugs may be fired more than once per combustion event. Multi-strike operating mode is RPM dependent.
    • Key ON, engine running. If no start, crank the engine.
      Fig 2: Normal Ignition Firing Pattern
      G04587238Courtesy of FORD MOTOR CO.

    Are the patterns even and is the average value of spark plug firing voltage between 9 kV and 15 kV (higher during engine crank/no start)? 

    Yes No
    GO to Pinpoint Test Z . GO to  JC6.
  6. JC6 IGNITION PATTERN EVALUATION 

    Is the ignition pattern normal? 

    Yes No
    GO to  JC7. GO to  JC8.
  7. JC7 TEST DIRECTION 

    Were you directed to this pinpoint test from pinpoint test step A8? 

    Yes No
    GO to PINPOINT TEST A step 9 . GO to  JC8.
  8. JC8 CHECK FOR MISSING SPARK PATTERNS 
    • Observe for missing spark pattern.
      Fig 3: Missing Spark Pattern
      G04587239Courtesy of FORD MOTOR CO.

    Is the spark pattern inconsistent? 

    Yes No
    INSPECT the spark plug wires for missing cylinders. MEASURE the resistance of the spark plug wires. INSTALL a new spark plug wire if the resistance is greater than 7,000 ohms per 30.5 cm (1 foot). REFER to the appropriate ENGINE IGNITION article . CLEAR the DTCs. REPEAT the self-test.
    GO to  JE2.    		 GO to  JC9.
  9. JC9 CHECK FOR A HIGH SPARK PLUG FIRING VOLTAGE 
    • Observe for a high spark plug firing voltage.
    Fig 4: High Spark Plug Firing Voltage
    G04587240Courtesy of FORD MOTOR CO.

    Is the average value of the spark plug firing voltage greater than 15 Kv? 

    Yes No
    INSPECT the spark plug wires for missing cylinders. MEASURE the resistance of the spark plug wires. INSTALL a new spark plug wire if the resistance is greater than 7,000 ohms per 30.5 cm (1 foot). REFER to the appropriate ENGINE IGNITION article .
    CLEAR the DTCs. REPEAT the self-test.    		 GO to  JC10.
  10. JC10 CHECK FOR LOW SPARK PLUG FIRING VOLTAGE 
    • Check the spark plug firing voltage average pattern.
      Fig 5: Low Spark Plug Firing Voltage
      G04587241Courtesy of FORD MOTOR CO.

    Is there consistently low spark plug firing voltage or sloping sparkline on one or more cylinders? 

    Yes No
    INSPECT the spark plug wires for missing cylinders. MEASURE the resistance of the spark plug wires. INSTALL a new spark plug wire if the resistance is greater than 7,000 ohms per 30.5 cm (1 foot). MEASURE the resistance of the spark plug(s). INSTALL a new spark plug (s) if the resistance is lower than 2,000 or higher than 20,000 ohms. REFER to the appropriate ENGINE IGNITION article .
    CLEAR the DTCs. REPEAT the self-test.    		 GO to  JC11.
  11. JC11 CHECK FOR EVENESS BETWEEN CYLINDERS 
    • Check the spark plug firing voltage average pattern.
      Fig 6: Spark Plug Firing Voltage (Uneven Pattern)
      G04587242Courtesy of FORD MOTOR CO.

    Is the evenness of spark plug firing voltage greater than 6 kV? 

    Yes No
    INSPECT the spark plug wires for missing cylinders. MEASURE the resistance of the spark plug wires. INSTALL a new spark plug wire if the resistance is greater than 7,000 ohms per 30.5 cm (1 foot). CHECK for damaged spark plugs or narrow spark plug gaps. MEASURE the resistance of the spark plug(s). INSTALL a new spark plug(s) if the resistance is lower than 2,000 or higher than 20,000 ohms. REFER to the appropriate ENGINE IGNITION article .
    CLEAR the DTCs. REPEAT the self-test.    		 GO to Pinpoint Test Z .
  12. JC12 DTC P0301 THROUGH P0306: MISFIRE ON CYLINDERS 1 THROUGH 6 

    Are DTCs P0300, P0301, P0302, P0303, P0304, P0305, or P0306 present? 

    Yes No
    GO to  JC13. GO to  JC14.
  13. JC13 CHECK FOR SPARK AT THE CYLINDER(S) INDICATED BY THE DTC(S) 
    • Disable the inertia switch.
    • Disconnect the spark plug wire(s) from the spark plug(s).
    • Connect the Air Gap spark tester 303-D037 (D81P-6666-A) or its equivalent to a spark plug wire.
    • Check for spark while cranking the engine.

    Is the bluish-white spark present? 

    Yes No
    GO to  JC16. INSPECT the spark plug wires for missing cylinders. MEASURE the resistance of the spark plug wires. INSTALL a new spark plug wire(s) if the resistance is greater than 7,000 ohms per 30.5 cm (1 foot). REFER to the appropriate ENGINE IGNITION article . If the spark plug wires are OK,
    GO to  JC15.
  14. JC14 CHECK FOR SPARK AT ALL CYLINDERS 
    • Disable the inertia switch.
    • Disconnect the spark plug wire(s) from the spark plug(s).
    • Connect the Air Gap spark tester 303-D037 (D81P-6666-A) or its equivalent to a spark plug wire.
    • Check for spark while cranking the engine.

    Is the bluish-white spark present? 

    Yes No
    GO to  JC16. INSPECT the spark plug wires for missing cylinders. MEASURE the resistance of the spark plug wires. INSTALL a new spark plug wire(s), if the resistance is greater than 7,000 ohms per 30.5 cm (1 foot). REFER to the appropriate ENGINE IGNITION article . If the spark plug wires are OK,
    GO to  JC15.
  15. JC15 CHECK THE SECONDARY COIL RESISTANCE FOR THE MISSING CYLINDERS 
    NOTE: Two adjacent coil towers share a common coil and are called a matched pair. For 6-tower coil pack (6 cylinder) applications, the matched pairs are 1 and 5, 2 and 6, and 3 and 4. For Mustang the matched pairs are 1 and 4, 2 and 5, and 3 and 6. For 4-tower coil pack (4 cylinder) applications, the matched pairs are 1 and 4, and 2 and 3.
    • Key in OFF position.
    • Ignition coil pack disconnected.
    • Disconnect spark plug wires from the coil pack.
    • Measure the resistance of each matched pair.

    Is the resistance between 9,500 and 15,500 ohms? 

    Yes No
    GO to Pinpoint Test Z . INSTALL a new ignition coil pack.
    CLEAR the DTCs. REPEAT the self-test.
  16. JC16 CHECK THE SPARK PLUGS 
    • Key in OFF position.
    • Check for damaged spark plugs or narrow spark plug gaps.

    Are the plugs OK? 

    Yes No
    GO to  JC17. REPAIR the spark plug(s). ADJUST the gap or INSTALL a new spark plug(s) as necessary. REFER to the appropriate ENGINE IGNITION article .
    CLEAR the DTCs. REPEAT the self-test.
  17. JC17 CHECK THE SPARK PLUG RESISTANCE 
    • Measure the spark plug resistance.

    Is the resistance between 2,000 and 20,000 ohms? 

    Yes No
    GO to Pinpoint Test Z . INSTALL a new spark plug(s). REFER to the appropriate ENGINE IGNITION article .
    CLEAR the DTCs. REPEAT the self-test.
  18. JC18 DTC P050B: COLD START PERFORMANCE 

    Are any other codes besides P050B present? 

    Yes No
    REPAIR all other powertrain related diagnostic trouble codes (DTCs) first. GO to  JC19.
  19. JC19 CHECK THE SPARK CAPTURE CIRCUIT 
    • Access the PCM and monitor the IGNPCM_F PID.

    Is a concern indicated? 

    Yes No
    GO to  JC21. GO to  JC20.
  20. JC20 CHECK THE IGNITION TIMING PID 
    • Access the PCM and monitor the IGNX_F PIDs.

    Is a concern indicated? 

    Yes No
    Visually inspect the coil pack harness for damage, exposed wiring, water contamination, corrosion, and correct assembly. REPAIR as necessary.
    CLEAR the DTCs. REPEAT the self-test.    		 GO to  JC21.
  21. JC21 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 to FLASH 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.
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