By main coil、Secondary coil、Magnetic core、Switching transistor and other auxiliary components，The main coil is charged by the battery，Secondary coil discharge spark plug ignition，The triode is responsible for switching。Charging time is controlled by battery voltage and engine speed、Ensure consistent energy for each charge，Ignition coils are available in 3-wire and 4-wire types，Wire 3 is the positive power supply、negative、Switch control (ECU command)，An additional ignition detection line is added to line 4，Able to detect whether the spark plug ignites (whether there is discharge current in the secondary coil)。 Speak simply，The ignition coil is the transformer，That is, increasing the voltage from dozens of volts to tens of thousands of volts，It’s just that the voltage input to the primary coil is provided by the electronic ignition。
2. Reasons for burnt ignition coil
The main reason for the burnout of the ignition coil is the aging and breakdown of the insulation layer or the damage of the switching transistor，A large spark plug gap causes a large load on the main coil、High fever、The insulation layer ages quickly，Small spark plug gap leads to large secondary coil discharge current、High fever、The insulation layer ages quickly，The assembled ignition coil may have poor insulation material、The internal resistance of the coil is large and the heat is generated、The lifespan of the tertiary tube will be shorter if the quality of the tertiary tube is not high。 If it is always burned out，It will burn out again soon after replacement，What is the reason for this，Some are summarized below: 1.Let’s look at the generator problem first，If the power generation is too high，If the load of the ignition coil is too heavy, it is easy to burn out，But if the power generation is really too high，Then body electrical appliances，Such as light bulbs, etc.，The city is often damaged;Of course, quality issues with accessories cannot seabet appbe ruled out，So it is best to measure the power generation first。2.The spark plug gap is too large，Adjust the gap or replace the spark plug;3.Bad quality of gasoline，Try changing to higher grade gasoline;4.Incorrect cylinder compression ratio，Adjust compression ratio;5.Program failure occurs on the computer board，You can go to the repair shop to use a computer to check the car，Just clear the error information。If it still doesn’t work，There may be a problem with your car’s transmission。6.Power supply voltage is unstable;7.The resistance of the high-voltage line is abnormal，Replace high-voltage wire;8.There is a short circuit on the secondary side;9.The primary current of the ignition controller is too high, causing the ignition coil to overheat;10.Exposed to high temperature，There is a problem with the high pressure wave and the work is not good;11.There is a small chance that it is a problem with the coil itself，You can try another brand;12.The igniter integrated block is not working properly; The ignition coil itself is a transformer，This is like a transformer in a household appliance，When the voltage changes within the specified range，It will not burn the transformer，Usually burning the transformer occurs when the transformer is overloaded，So when solving this problem, we must try our best to find out the cause of overload or component aging。
3. Detection method
The crankshaft position sensor (CKP) and camshaft position sensor (CMP) are detected normally，But no high pressure fire，Usually a break in the ignition coil assembly power lead。 (1) Test with high impedance multimeter and light-emitting diode: models without distributor ignition，Unplug the primary winding plug of the 4-channel ignition coil first，Use a high-impedance multimeter to test holes 3 to 4，Voltage should not be less than 11 V。Respectively at 1、4 holes and 3、Connect the 4 holes to the LED，If the LED does not flash when the engine is started，Indicates that there is no low voltage signal，Focus on checking low-voltage circuits。Power transistor failure will affect the ignition control signal，The power transistor is the ignition control signal amplifier，Turn off ignition switch，Connect the light-emitting Seabetdiode between the battery positive terminal and the power transistor terminal a，Start the engine，Let it run for 10s，If the LED does not light up，Power transistor should be replaced。 (2) Resistance value test: The resistance value of the ignition coil is directly related to the quality of ignition performance，If there is no fire or weak spark，The primary winding should be inspected、Resistance value of secondary winding，Unplug the high-voltage wires of each cylinder，Measured at 20℃1、Between 4 cylinders，3、Resistance value between 4 cylinders。If the resistance value is within the range specified by the manufacturer, it means it is normal，If the resistance value is too low, it indicates an internal short circuit;If the resistance value is too high, it means an internal circuit break。If the measured value does not match the manufacturer’s specifications, it must be replaced。 (3) The main characteristic when the ignition coil is about to be damaged is that the ignition coil heats up、Hot hand。 (4) Traditional car inspections for ignition coil faults mainly focus on high-voltage flashover，Under the premise that the low-voltage circuit is normal，If the ignition coil is not faulty，There should be strong blue sparks during flashover。The ignition coil of electronic fuel injection is mainly used to measure the impedance of the primary and secondary windings and use light-emitting diodes to measure circuit continuity。 (5) If a cylinder spark plug is found to have no fire or is working poorly，You can unplug the high-voltage branch line of the cylinder，Connect a new spark plug，Flashover 8mm outside the cylinder from the cylinder block，As normal，Indicates that the fault is in the original spark plug。 Suddenly no fire or weak spark while driving，You can use an infrared thermometer or hand touch to determine whether the ignition coil or ignition module has an internal short circuit or open circuit fault。When determining fault，You can also restart，Whether it can be started or not，You can measure the temperature of the ignition coil shell to make a judgment。 ① Ignition coil overheating: the surface temperature of the ignition coil is greater than 95℃，Indicates internal short circuit of ignition coil，Must be replaced。 seabet io②The ignition coil is too cold: the surface temperature of the ignition coil is equal to the ambient temperature during startup，Explains the internal circuit break of the ignition coil，Must be replaced。 ③Ignition module overheating: The ignition module temperature is higher than 100℃，Indicates an internal short circuit in the ignition module，Must be replaced。 ④The ignition module is too cold: the ignition module and the ambient temperature are equal during startup，Explains the internal circuit break in the ignition module，Must be replaced。(Pictures and text from the Internet，If copyright is involved, please contact us to delete)
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