How to Diagnose Faults in the Automotive Ignition System?

[Karla]

ECU-controlled ignition system fault diagnosis methods are as follows: 1. ECU-controlled ignition system: A typical ignition coil generally consists of two coils, the primary coil and the secondary coil. These two coils play the main role in ignition, as they can convert voltage between high and low levels. Because the primary coil has more turns than the secondary coil, the ignition coil can transform the vehicle's low-voltage electricity into high voltage. 2. Principle: When current is conducted to the primary coil, electrical energy is converted into magnetic energy within the primary coil, gradually forming a strong magnetic field around the coil, which stores magnetic energy in the coil's iron core. Typically, the coil is equipped with a switching device. When the switching device is used to break the primary coil's circuit, the magnetic field rapidly decreases due to the absence of current. Meanwhile, the secondary coil, having fewer turns, induces a very high voltage. Understanding this principle allows for diagnostic troubleshooting when initial judgment indicates a fault in the ignition system.

[LondynDella]

I've repaired quite a few cars, and ignition system issues are quite common. Diagnosis can start from simple places. First, check if the spark plugs are carbon-fouled or worn, pull them out to see if the electrodes are blackened. If the spark plugs are fine? Then test the ignition coil, use a multimeter to measure the resistance value, normally it should be around 0.5 to 1.5 ohms. Loose wire connections are also common, gently shake the high-voltage wires to see if there's any looseness. Make sure the battery terminals are clean and free of corrosion. If none of these checks reveal the problem, it might be a control module failure—it's best not to tamper with it yourself, using professional tools or taking it to a repair shop to read the fault codes is more reliable. Pay attention to engine shaking or difficulty starting while driving normally, early detection can save a lot of trouble.

[SanAyla]

Diagnosing ignition system issues requires attention to safety. If the car fails to start or stalls midway, immediately pull over to a safe area—don't attempt repairs on the road. I typically start by opening the hood to check for spark output from the spark plugs, using a simple test light or listening to engine sounds. Damaged insulation on high-voltage wires can cause short circuits, so visually inspect for cracks. An overheating ignition coil indicates a problem—feel for abnormally high temperatures. Also test the battery voltage, as readings below 12V can affect overall performance. Don't force repairs without proper tools; calling a tow truck or mechanic is safer. Regular maintenance like replacing spark plugs helps prevent such failures.

[OliveRose]

Ignition Fault Diagnosis Method: First, check the condition of the spark plugs to see if they are aged or blackened; measure whether the ignition coil resistance is within the standard range; inspect the high-voltage wires for cracks or looseness; using an OBD scanner to read fault codes is crucial for modern vehicles; poor contact in the control module or sensor faults can also affect ignition output. Simple steps start from visual inspection to tool testing. Pay attention to changes in engine running sounds during daily use.