What certificate does a comprehensive maintenance worker need?

What documents do comprehensive maintenance workers need as follows:

The automobile mechanic certificate is a professional qualification certificate issued by the Human Resources and Social Security Bureau, which is usually registered in the local personnel bureau to take the exam. Automobile mechanic is a modern technician engaged in automobile inspection, maintenance, repair and debugging. Automobile mechanics generally use tools, fixtures, measuring tools, instruments and maintenance equipment to detect, maintain, repair and debug automobiles.

The occupations of automobile maintenance workers are divided into five grades, namely: primary (national vocational qualification level 5), intermediate (national vocational qualification level 4), advanced (national vocational qualification level 3), technician (national vocational qualification level 2) and senior technician (national vocational qualification level 1).

Assessment methods: divided into theoretical knowledge examination and skill operation examination. The theoretical knowledge test adopts closed-book written test, and the skill operation test adopts on-site actual operation. Both the theoretical knowledge test and the skill operation test adopt the percentile system, and those who have scored 60 or above in both courses are qualified. The identification of technicians and senior technicians must also be comprehensively reviewed.

Contents of practical (intermediate) vocational qualification certificate for automobile machinery maintenance:

Maintenance of engine components.

Valve timing detection, matching of piston and piston ring, water pump maintenance, piston connecting rod device and reflection, experimental adjustment of diesel fuel injector, gas detection, hinge pin of engine valve seat and exhaust gas detection of gasoline engine.

Maintenance of chassis components.

Maintenance of transmission, front wheel brake, steering gear, hydraulic vacuum supercharger, rear axle drum brake and main reducer.

Fault diagnosis and cleaning.