P0300CriticalSpark Plug & HT Coil • Car, Truck, Bike
Random / Multiple Cylinder Misfire Detected
रैंडम / मल्टीपल सिलेंडर मिसफायर खराबी — common code demo from the VahanScan app’s full DTC library.
Multimeter Testing Specifications & Pinouts
- Power Pin (VCC)
- 12V Battery feed at Ignition Coil Pin 1
- Signal Pin
- 5V / 12V trigger pulse from ECU
- Ground Pin Continuity
- Chassis ground / ECU ground pin
- Coil / Heater Resistance
- Primary: 0.6 – 1.8 Ω | Secondary: 8.5 – 15.0 kΩ
💡 Use peak voltage adapter or duty-cycle setting for ECU trigger pulse.
Fault Symptoms
- •Flashing Check Engine Light (MIL blinking continuously)
- •Severe engine shudder and sudden power loss
- •Unburnt fuel smell in exhaust gas
- •Difficulty starting or backfiring
लक्षण
- •मीटर में चेक इंजन लाइट का लगातार ब्लिंक करना
- •इंजन का जोर-जोर से हिलना और पिकअप एकदम खत्म होना
- •साइलेंसर से कच्चे पेट्रोल या डीजल की महक
- •गाड़ी का लेट स्टार्ट होना या बैकफायर मारना
Probable Causes
- •Worn spark plug electrode gap or heavy carbon fouling
- •Ignition coil primary/secondary winding failure
- •Clogged fuel injector nozzle or low fuel rail pressure
- •Intake manifold vacuum leak or low cylinder compression
संभावित कारण
- •स्पार्क प्लग का घिस जाना या बहुत ज्यादा कार्बन जमना
- •इग्निशन HT कॉइल का कमजोर होना या करंट लीक होना
- •फ्यूल इंजेक्टर जाम होना या पेट्रोल का दबाव कम होना
- •मैनिफोल्ड से हवा की लीकेज या इंजन कम्प्रेशन कम होना
Step-by-Step Repair Guide
- 1.1. Remove spark plugs; inspect electrode gap (0.8 - 0.9 mm) and clean carbon.
- 2.2. Test primary HT coil resistance: 0.6 Ω – 1.8 Ω. Secondary coil: 8.5 kΩ – 15 kΩ.
- 3.3. Verify 12V pulse signal at ignition coil input connector during cranking.
- 4.4. Check injector spray pattern and fuel pressure (minimum 3.0 bar for petrol / 250+ bar CRDI).
- 5.5. Reset MIL code with VahanScan and test drive.
Physical Sensor Location: Spark plugs inside cylinder head; HT coils mounted on top of valve cover or chassis frame.
Diagnose this code in your garage
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