Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Ignition System Inspection
- Misfire Inspection
- Check the cylinder where the misfire occurs after replacing the ignition coil of the cylinder where the misfire has occurred with the ignition coil of the other cylinder.
- Does the misfiring cylinder change?
YES
- Go to "ignition Coil Waveform Inspection" procedure.
NO
- Repair as necessary except for the ignition coils and go to "FUEL SYSTEM INSPECTION " procedure.
- Ignition coil waveform inspection
- Ignition "ON" and engine "ON".
- Measure the voltage between control terminal of ignition soil harness connector and chassis ground.
Specification: Refer to Waveform
Spark retention time - Approx. 1.2ms
CH. A - Ignition Max 31V
- Is the measured waveform within specification?
YES
Repair as necessary except for the ignition coils and go to "FUEL SYSTEM INSPECTION " procedure.
NO
Go to "Spark Plug Cable & Ignition Coil Inspection" procedure.
- Spark Plug Cable & Ignition Coil Inspection
- Visually/physically inspect the spark plug cable and ignition coil related to the misfiring cylinder(s) for the following conditions.
- Damage, cracks, carbon and flashover
- Poor connection or damaged harness
- Connected to the incorrect cylinders at the ignition coil and spark plug
- Measure the resistance of the spark plug cable related to the misfiring cylinder(s)
Specification: 5.6kΩ/m ±20%
- Measure the resistance of the primary and secondary ignition coil related to the misfiring cylinder(s)
Specification: Primary Ignition Coil Resistance : 0.56~0.68Ω at 20°C(68°F)
Secondary Ignition Coil Resistance : 6~8kΩ at 20°C(68°F)
- Was a problem found in any of the above areas?
YES
- Repair or replace as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure.
NO
- Go to next step as below.
- Visually/physically inspect the spark plug cable and ignition coil related to the misfiring cylinder(s) for the following conditions.
- Spark Plug Inspection
- Visually/physically inspect the spark plug related to the misfiring cylinder(s) for the following conditions.
- Damaged insulation, Worn electrodes, Oil or fuel fouled, Loose terminals and cracks.
- Check for electrode gap : 1.0 - 1.1 mm (0.039 - 0.043 in.)
- Check if the spark plug for the relevant cylinder is lighter in color than the other plugs.
- Was a problem found in any of the above areas?
YES
- Repair or replace as necessary. Go to "VERIFICATION OF VEHICLE REPAIR " procedure.
NO
- Go to next step as below.
- Visually/physically inspect the spark plug related to the misfiring cylinder(s) for the following conditions.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.