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Home >> Mazda >> 2001 >> B2500 SE, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> System Tests >> Test JB: Secondary Ignition >> Diagnostic Aids

Diagnostic Aids

  1. 1) Preliminary Test

    Ensure battery is fully charged and all accessories are off. Check all wiring harnesses and connectors for damage, burned or overheated insulation. Ensure all coils and plug wires are securely connected. Repair as necessary and perform DRIVE CYCLE PROCEDURES  under ADDITIONAL SYSTEM FUNCTIONS. Ensure OBD-II DRIVE CYCLE PROCEDURES are performed to verify repair. If no problems are found, proceed as follows:
    • On models equipped with coil pack system, go to next step (if using engine analyzer) or go to step  20) (if not using engine analyzer).
    • On models equipped with coil on plug system, go to step  15).

  2. 2) Connect Engine Analyzer

    DTC P0350 is set when PCM does not receive a valid Ignition Driver Module (IDM) pulse signal from ignition module integrated in PCM. Possible causes are:
    • IGN START/RUN Circuit Open Or Short ed
    • Coil Driver Circuit Open, Or Shorted To GND Or VPWR
    • Faulty Coil
    • Faulty Powertrain Control Module (PCM)

    Install Rotunda Engine Analyzer (010-00869). Go to next step.

  3. 3) Check For Ignition Pattern

    Crank engine and observe scope pattern. If scope pattern is flat (no spark on all cylinders), turn ignition switch to OFF position and check IGN START/RUN circuit. Check all related fuses and fuse links. If fuse or fuse link is blown, check IGN START/RUN circuit for short to GND. Repair as necessary and perform DRIVE CYCLE PROCEDURES  under ADDITIONAL SYSTEM FUNCTIONS. Ensure OBD-II DRIVE CYCLE PROCEDURES are performed to verify repair.
    4. NOTE: Spark plugs are fired up to 4 strikes per ignition cycle. Multi-Strike operating mode is dependent on PCM calibration and is operational only with engine speed at less than 2000 RPM. With engine speed at more than 2000 RPM, spark plugs are fired once per ignition cycle.

  4. 4) Check For Normal Ignition Pattern
    Start engine and allow to idle. Observe scope pattern and check average spark output voltage and variation of pattern. If spark patterns are not even and average spark plug firing voltage is not 9-15 kilovolts, go to next step. If problem is intermittent and spark pattern is even and average value of spark plug firing voltage is 9-15 kilovolts, fault is unable to be duplicated at this time. Go to TEST Z, step  1). If average spark plug firing voltage is 9-15 kilovolts, ignition system is functioning properly. If directed here from TROUBLE SHOOTING - NO CODES article, return to symptom test that directed you here. If directed here from TEST HD, step 3)  , return to TEST HD, step  4). If directed here from TEST A, step 6)  , return to TEST A, step  6).

  5. 5) Check For 2 Missing Spark Patterns On Same Coil

    Observe scope pattern. If spark is not missing from 2 cylinders on same coil, go to next step. If spark is missing from 2 cylinders on same coil, check spark plug wires and spark plugs on missing cylinders. Measure resistance of spark plug wires. Spark plug wire resistance should be 7 k/ohms or less per foot. Measure resistance of spark plugs. Spark plug resistance should be 2-20 k/ohms. Repair as necessary and retest. If plug wires and plugs are okay, go to TEST JE, step  1).

  6. 6) Check For One Missing Spark Pattern

    Observe scope pattern. If spark is not missing from one cylinder, go to next step. If spark is missing from one cylinder, check spark plug wires and spark plugs on missing cylinders. Measure resistance of spark plug wires. Spark plug wire resistance should be 7 k/ohms or less per foot. Measure resistance of spark plugs. Spark plug resistance should be 2-20 k/ohms. Repair as necessary. Perform DRIVE CYCLE PROCEDURES  under ADDITIONAL SYSTEM FUNCTIONS. Ensure MISFIRE & FUEL MONITOR PROCEDURES are performed to verify repair.

  7. 7) Check For High Spark Plug Firing Voltage

    Observe scope pattern and check average spark firing voltage and pattern. If spark plug firing voltage is 15 kilovolts or less, go to next step. If average spark plug firing voltage is more than 15 kilovolts, check spark plug wires and spark plugs on affected cylinders. Measure resistance of spark plug wires. Spark plug wire resistance should be 7 k/ohms or less per foot. Measure resistance of spark plugs. Spark plug resistance should be 2-20 k/ohms. Repair as necessary. Perform DRIVE CYCLE PROCEDURES  under ADDITIONAL SYSTEM FUNCTIONS. Ensure MISFIRE & FUEL MONITOR PROCEDURES are performed to verify repair.

  8. 8) Check For Low Spark Plug Firing Voltage

    Observe scope pattern and check average spark plug firing voltage and pattern. If spark plug firing voltage is not consistently low on one or more cylinders, go to next step. If spark plug firing voltage is consistently low in one or more cylinders, check spark plug wires and spark plugs on affected cylinders. Measure resistance of spark plug wires. Spark plug wire resistance should be 7 k/ohms or less per foot. Measure resistance of spark plugs. Spark plug resistance should be 2-20 k/ohms. Repair as necessary. Perform DRIVE CYCLE PROCEDURES  under ADDITIONAL SYSTEM FUNCTIONS. Ensure MISFIRE & FUEL MONITOR PROCEDURES are performed to verify repair.

  9. 9) Check For Eveness Between Cylinders

    Observe scope pattern. If spark plug firing voltage variation is more than 6 kilovolts, check spark plug wires and spark plugs on affected cylinders. Measure resistance of spark plug wires. Spark plug wire resistance should be 7 k/ohms or less per foot. Measure resistance of spark plugs. Spark plug resistance should be 2-20 k/ohms. Repair as necessary. Perform DRIVE CYCLE PROCEDURES  under ADDITIONAL SYSTEM FUNCTIONS. Ensure MISFIRE & FUEL MONITOR PROCEDURES are performed to verify repair. If spark plug firing voltage variation is 6 kilovolts or less, fault is unable to be duplicated at this time. Go to TEST Z, step  1).
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 9) to step 15). No test procedures have been omitted.

  10. 15) DTC P0301-P0310: Misfire On Cylinders No. 1-10

    If DTC P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308, P0309 or P0310 is present, go to next step. If specified DTCs are not present, go to step  17).

  11. 16) Check For Spark At Cylinder(s) Indicated By DTC(s)

    Disconnect Inertia Fuel Shutoff (IFS) switch. Disconnect ignition coil(s) from spark plug(s). Install Spark Tester (303-D037) to coil(s). Check for spark at cylinder(s) while cranking engine. If Blue-White spark is present, turn ignition switch to OFF position and go to step  18). If Blue-White spark is not present, measure resistance of spark plug(s). If resistance is not 2-20 k/ohms, replace affected spark plug(s) and go to TEST JF, step  1).

  12. 17) Check For Spark At All Cylinders

    Disconnect Inertia Fuel Shutoff (IFS) switch. Disconnect ignition coil(s) from spark plug(s). Install Spark Tester (303-D037) to coil(s). Check for spark at all cylinders while cranking engine. If Blue-White spark is consistent between all cylinders, turn ignition switch to OFF position and go to next step. If Blue-White spark is not consistent between all cylinders, measure resistance of spark plug(s). If resistance is not 2-20 k/ohms, replace affected spark plug(s) and go to TEST JF, step  1).

  13. 18) Check Spark Plugs

    Remove and inspect spark plugs for damage, wear, carbon deposits and proper plug gap. Adjust gap or replace plugs as necessary. Perform DRIVE CYCLE PROCEDURES  under ADDITIONAL SYSTEM FUNCTIONS. Ensure MISFIRE & FUEL MONITOR PROCEDURES are performed to verify repair. If spark plugs are okay, go to next step.

  14. 19) Check Spark Plug Resistance

    Measure resistance of spark plugs. If resistance is not 2-20 k/ohms, replace affected spark plug. Perform DRIVE CYCLE PROCEDURES  under ADDITIONAL SYSTEM FUNCTIONS. Ensure MISFIRE & FUEL MONITOR PROCEDURES are performed to verify repair. If spark plug resistance is within specification, proceed as follows:
    • If problem is intermittent, go to TEST Z, step  1).
    • If directed here from TROUBLE SHOOTING - NO CODES article, return to symptom test that directed you here.
    • If directed here from TEST HD, step 3)  , return to TEST HD, step  4).
    • If directed here from TEST A, step 6)  , return to TEST A, step  6).

  15. 20) DTC P0301-P0310: Misfire On Cylinders No. 1-10

    If DTC P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308, P0309 or P0310 is present, go to next step. If specified DTCs are not present, go to step  22).

  16. 21) Check For Spark At Cylinders Indicated By DTCs

    Disconnect Inertia Fuel Shutoff (IFS) switch. Disconnect spark plug wire(s) from spark plug(s). Install Spark Tester (303-D037) to spark plug wire. Check for spark from affected spark plugs while cranking engine. If Blue-White spark is present, turn ignition switch to OFF position and go to step  23). If Blue-White spark is not present, measure resistance of spark plug wires. Spark plug wire resistance should be 7 k/ohms or less per foot. Repair as necessary. Perform DRIVE CYCLE PROCEDURES  under ADDITIONAL SYSTEM FUNCTIONS. Ensure MISFIRE & FUEL MONITOR PROCEDURES are performed to verify repair. If spark plug wire resistance is within specification, go to TEST JE, step  1).

  17. 22) Check For Spark At ALL Spark Plugs

    Disconnect Inertia Fuel Shutoff (IFS) switch. Disconnect spark plug wires from spark plugs. Install Spark Tester (303-D037) to spark plug wire. Check for spark from each spark plug while cranking engine. If Blue-White spark is consistent between all plugs, turn ignition switch to OFF position and go to next step. If Blue-White spark is not consistent between all plugs, measure resistance of spark plug wires. Spark plug wire resistance should be 7 k/ohms or less per foot. Repair as necessary. Perform DRIVE CYCLE PROCEDURES  under ADDITIONAL SYSTEM FUNCTIONS. Ensure MISFIRE & FUEL MONITOR PROCEDURES are performed to verify repair. If spark plug wire resistance is within specification, go to TEST JE, step  1).

  18. 23) Check Spark Plugs

    Remove and inspect spark plugs for damage, wear, carbon deposits and proper plug gap. Adjust plug gap or replace plug(s) as necessary. Perform DRIVE CYCLE PROCEDURES  under ADDITIONAL SYSTEM FUNCTIONS. Ensure MISFIRE & FUEL MONITOR PROCEDURES are performed to verify repair. If spark plugs are okay, go to next step.

  19. 24) Check Spark Plug Resistance

    Measure resistance of spark plugs. If resistance is not 2-20 k/ohms, replace affected spark plug. Perform DRIVE CYCLE PROCEDURES  under ADDITIONAL SYSTEM FUNCTIONS. Ensure MISFIRE & FUEL MONITOR PROCEDURES are performed to verify repair. If spark plug resistance is within specification, proceed as follows:
    • If problem is intermittent, go to TEST Z, step  1).
    • If directed here from TROUBLE SHOOTING - NO CODES article, return to symptom test that directed you here.
    • If directed here from TEST HD, step 3)  , return to TEST HD, step  4).
    • If directed here from TEST A, step 6)  , return to TEST A, step  6).
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