In terms of operation, the black wire is grounded, the red wire is connected to the negative terminal of the ignition coil, the engine is running, and the display screen will display the closing angle of the primary side of the ignition coil. Refer to the following procedures for details:
1. The multimeter can simply measure the resistance of the two high-voltage ends (the end connected to the spark plug), but it cannot completely judge the fault of the ignition coil!
2. The voltage value between the terminals of the independent ignition coil plug is different due to the difference in the previous one, so the quality of the ignition coil cannot be judged;
3. The three-wire is generally power, ground, and ECU signals, and the four-wire will have a speed feedback output; there are also special ones, such as the third-wire QQ goes first, there is no ECU signal, and one is grounded;
4. Any coil has a secondary coil and a primary coil, just like a transformer. The coils used in the distributor are output by a high-voltage head and then distributed to each cylinder.