Frequency coefficient of use of automobile's electronic connection harness
The electrical system load is related to the use and working status of electrical equipment. The working status of electrical equipment depends on the season, environment, traffic status and personal hobbies. Complicated use conditions make the calculation of electrical system load difficult. For the convenience of analysis and calculation, the concept of frequency coefficient of the use of electrical equipment is introduced to calculate the power consumption of the vehicle and the design of the wiring harness.
Automotive electrical equipment has different frequency coefficients in different seasons and environments. In this paper, μs, μo, and μw are used to denote the frequency coefficients of the use of electrical equipment in three cases, which are independent of summer, seasonal climate, and winter.
The electrical equipment included in the three cases is as follows:
μs (related to summer): Radiator electric fan, wiper, air-conditioning compressor and blower wiring harness;
μo (independent of seasonal climate): Continuous work equipment, short-time work equipment (except wipers) and equipment wiring harnesses used randomly (except air-conditioning compressors and blowers);
μw (related to winter): radiator fan, wiper and blower wiring harness.
 
Example: The control relationship between the vehicle air-conditioning wiring harness system and the EMS wiring harness system:
 
From this control logic schematic diagram, we can understand the control logic relationship between the air conditioning system and the electronic fuel injection control system: After receiving the input signal of the air conditioning system, the ECM control unit outputs ground potential signals at the A2 and C1 pins to control the operation of the air conditioning compressor and cooling fan.
The parameters that need to be confirmed in this system are: The signal type (analog signal, digital signal (including switch signal), pulse signal) and specific parameters of the signal output by the C6 and C12 pins of the air conditioner controller. If the digital signal is 0V, 5V or 12V, confirm the type and specific parameters of the output signal of the C7/B8/C1/A2 pin of the EMS.