The Ministry of Transport approved the release of the recommendation industry standard “Technical Specifications for Automobile Evolution Performance Maintenance” (JT/T 1474-2023) on June 25, 2023, which will be implemented from September 25, 2023.
1. Develop background
In order to thoroughly implement the Central Committee of the Communist Party of China and the State Council’s “Opinions on Comprehensively Strengthening Ecological Environmental Protection and Resolutely Fighting Pollution Prevention and Control,” and the requirements of the State Council’s “Three -year Action Plan to Win the Blue Sky Defense War”, in conjunction with the implementation of the “Diesel Vehicle Pollution Control Battle Action Plan for Pollution Governance, “Notice on Establishing the Implementation of Automobile Evidence Inspection and Maintenance System” proposed in the car emission system inspection and maintenance (I/M) system implementation, standardized and guided automobile maintenance enterprises to carry out automotive emission system maintenance operations, and the relevant units of the Ministry of Transport organized relevant units to carry out the development of the Ministry of Transportation. The formulation of industry standards “Technical Specifications for the Maintenance of Automobile Evolution”.
2. Standard positioning and role
This standard specifies the maintenance process, key component operation items and requirements of car emissions performance, and is suitable for the maintenance and repair of unqualified cars.
The standards mainly solve problems such as irregular operations, unclear operating projects, and depth depth of operations in the automotive maintenance system of the automotive maintenance industry. Performance, thereby effectively controlling and reducing the emissions of automotive pollutants. Standards are of great significance to implement the testing and maintenance (I/M) system and the pollution control of diesel vehicles, and winning the Blue Sky Defense War, and will contribute to energy conservation and emission reduction of energy conservation and emission by the transportation industry.
Third, the main content of the standard
(1) Maintenance process
Car maintenance is an important measure to maintain or restore the technical performance of the vehicle. The Ministry of Transport has established a vehicle maintenance system and standard system. This standard is fully connected with the technical standards of many years of maintenance. Make specific regulations. In order to improve the efficiency of the in factory diagnosis of unqualified vehicles and prevent blind maintenance and repair, the standard stipulates the maintenance process of unqualified vehicles in the factory, and guide the maintenance workers to analyze the cause of the vehicle in order to accurately determine the faulty area and the operation items. The main processes include the following aspects:
1. In order to improve the accuracy and maintenance quality of the discharge detection and diagnosis, the vehicle first inspected the vehicle first. The standard was given 7 required items and requirements, including the idle state of the engine. , Cooling system, lubrication system, fuel supply system, and cylinder sealing.
2. Discharge and detection of vehicles, record the measurement value of the emission, because the car emissions pollutants are derived from the burning of fuel in the engine. It contains many ingredients, and the conditions generated are different. After the combustion process and after the burning, it was related to the processing during the exhaust process. Record specific emission values can provide the basis for the next diagnosis of maintenance personnel according to the emission value.
3. Use the diagnostic instrument to read the fault code to determine the items that need to be maintained; for vehicles that do not have a discharge code, use the diagnostic instrument to read the data flow of the vehicle’s electrical control unit (such as engine speed, water temperature, fuel injection pulse, intake flow,, inlet flow,,,, inlet flow, inlet flow,,, inlet flow flow, inlet flow, flowing flow, flowing flow, and air intake flow. Find the cause of the failure of air intake pressure, air intake temperature, oxygen sensor, explosion sensor, ignition time, throttle position sensor and other sensors) to find the cause of the fault and determine specific maintenance items.
4. When the diagnostic instrument fails to detect the failure, according to the emission values of the emission detection at the factory and the data of the vehicle’s discharge detection in the environmental inspection station, the special component maintenance items given in this standard are Diagnostic analysis and determine maintenance projects.
5. In order to ensure the quality of maintenance, it is required to perform initialization settings in response to the relevant electrical control system after the operation is required to ensure that the system function is normal and the vehicle is in a normal state.
6. After the above operations are completed, before the vehicle leaves the factory, the vehicle emission performance should be performed. Unqualified vehicles should be re -diagnosed and repaired.
(2) Key component operation projects and requirements
1. Operational project. There are many reasons for influencing the performance of automobile emissions and the unqualified emissions. During the formulation process, the standards systematically analyze the discharge failure mechanism and automobile emissions technology. The current influence factors of the technical configuration and emission performance of the vehicle emission system, referring to the maintenance operation requirements in the maintenance technology manual in the automotive production enterprise, according to the two categories of ignition engine and a combustible engine, divided into engine intake, exhaust, supply, supply, supply, and supply Oil, ignition, cooling and other systems have clearly clarified key component projects that are common and easy to cause discharge failure in the system to facilitate operational personnel to operate. For example, the key components of the engine intake system, according to the different weights of the emission performance, determine the air filter, turbocharger, turbocharged pressure sensor, turbocharged control solenoid valve, throw, throwing door sensor, air, air, air, air, air, air, air Flow sensors, air intake temperature sensors, and air intake pressure sensors are key parts.
2. Operation requirements. According to the regulations and standards of relevant departments and standards of the Ministry of Transport, the maintenance of the vehicle is mainly based on the content of cleaning, inspection, supply, lubrication, fastening, and adjustment. Generally, the problem of faults is effectively defined on the requirements of maintenance operations. If the operating requirements of the temperature saving device are required, the temperature -saving device shall have no stagnation or closure. When the cooling fluid temperature is higher than 100 ° C, the thermostat shall be turned on, and when the cooling fluid temperature is lower than 80 ° C, the thermostat should be the temperature. Can be closed.
Because there are many brands and models in the current use of car models, different vehicles are configured, the specific parameter values of each component, sensor, and control systems are large. Consider the standard of standards. Spark plugs, temperature vessels and other indicators with common parameters are clear. For other items, during the implementation of the standard, the maintenance operators shall be operated according to the provisions of this standard. The parameter values of the specific operating items shall query the vehicle maintenance manual determination.