Electronic control system circuit is mainly composed of engine control system (including fuel injection, ignition, emission control), automatic transmission and constant speed driving control system, brake anti-lock braking system, airbag control system and other circuits.
The car circuit generally adopts a single-wire system, parallel connection of electrical equipment, and negative ground. Accessories live wire (Acc line), key switch live wire (line 15).
The live wire/positive wire of the battery (line B or line 30) leads directly to the fuse box from the positive pole of the battery, and the live wire of the battery of the car is also connected to the live wire terminal of the starter, and then a thinner live wire is drawn from there.
Ignition instrument indicator line: the wire with electricity only when the ignition switch is in ON (working) and ST (starting) gears, and the ignition system, pre-magnetization, instrument system, indicator light, signal system, and electronic control must be connected with the car key important circuits.