Standard No.:	GB 17675-2025
English Name:	Steering system of motor vehicles—Basic requirements
Chinese Name:	汽车转向系 基本要求
Professional Classification:	GB    National Standard
Source Content Issued by:	SAMR;SAC
Issued on:	2025-12-02
Implemented on:	2026-7-1
Status:	to be valid
Superseding:	GB 17675-2021 Steering system of motor vehicles—Basic requirements
Target Language:	English
File Format:	PDF
Word Count:	21500 words
Translation Price(USD):	645.0
Delivery:	via email in 1~5 business day

ICS 43.040.50 CCST 23 National Standard of the People’s Republic of China GB 17675-2025 Replaces GB 17675-2021 Steering system of motor vehicles - Basic requirements 汽车转向系 基本要求 (English Translation) Issue date: 2025-12-02 Implementation date: 2026-07-01 Issued by the State Administration for Market Regulation of the People's Republic of China the Standardization Administration of the People's Republic of China Steering system of motor vehicles - Basic requirements 1 Scope This document specifies the technical requirements on steering systems of motor vehicles and the requirements on determination of the same type, and describes the corresponding test methods. This document is applicable to Categories M, N, and O vehicles specified in GB/T 15089. This standard is not applicable to: —— pneumatic transmission steering system; —— vehicles with autonomous steering system. Note: Autonomous steering system refers to a vehicle integrated composite electronic control system that makes the vehicle travel along a determined or corrected path and enables the driver to not have to hold dominant control over the vehicle by responding to the reception and transmission of signals outside the vehicle in addition to the automatic driving system. 2 Normative references The following documents contain requirements which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. GB/T 3730.1 Terms and definitions of motor vehicles, trailers and combination vehicle - Part 1: Types GB/T 3730.2 Road vehicle - Masses - Vocabulary and codes GB/T 3730.3 Motor vehicles and towed vehicles - Dimensions of vehicles - Terms and definitions GB/T 5053.3 Road vehicles - Connectors for the electrical connection of towing and towed vehicles - Definitions tests and requirements GB/T 5563 Rubber and plastics hoses and hose assemblies - Hydrostatic testing GB/T 7939.3 Connections for hydraulic fluid power - Test methods - Part 3: Hose assemblies GB/T 9574 Rubber and plastics hoses and hose assemblies - Ratios of proof and burst pressure to maximum working pressure GB/T 12540 Minimum turning circle diameter, turning clearance circle and swing-out value test method for motor vehicles and combination of vehicles GB 12676 Technical requirements and testing methods for commercial vehicle and trailer braking systems GB/T 15089 Classification of power-driven vehicles and trailers GB/T 20716.1-2025 Road vehicles - Connectors for the electrical connection of towing and towed vehicles (7-pole) - Part 1: Connectors for braking systems and running gears of vehicles with 24 V nominal supply voltage GB/T 20718-2006 Road vehicles - Connectors for the electrical connection of towing and towed vehicles - 13-pole connector for vehicles with 12V nominal supply voltage GB 21670 Technical requirements and testing methods for passenger car braking systems GB/T 34590 (all parts) Road vehicles - Functional safety GB 34660 Road vehicles - Requirements and test methods of electromagnetic compatibility Road vehicles - Symbols for controls, indicators and tell-tales 3 Terms and definitions For the purposes of this document, the terms and definitions given in GB/T3730.1, GB/T 3730.2, GB/T 3730.3, GB/T 12540, GB/T 15089, and GB/T 34590.1 as well as the following apply. 3.1 Basic terms 3.1.1 Steering system and equipment 3.1.1.1 steering system system for changing or maintaining the driving direction of a vehicle Note: It includes steering control equipment, steering transmission equipment, steered wheels and energy supply equipment (if any). [Source: GB/T 35360-2017, 2.1, modified] 3.1.1.2 steering control equipment operating mechanism in the steering system that controls the steering with or without the direct intervention of the driver Note: For the steering system in which the steering force is wholly or partially provided by the muscle strength of the driver, the steering control equipment includes all components that convert the steering control force into steering force by mechanical, hydraulic or electric means. 3.1.1.3 steering transmission equipment combination of parts and components that form a functional connection between the steering control equipment and the steered wheels for realizing control transmission and/or energy transmission Note: By the control and/or energy transmission mode, it may be classified into mechanical type, hydraulic type, electric type and various combinations thereof. 3.1.1.3.1 control transmission function of transmitting a control signal command to control the action of the steering equipment 3.1.1.3.2 energy transmission function of transmitting energy to steered wheels to control/adjust steering 3.1.1.4 steered wheels wheels whose moving direction can be changed directly or indirectly relative to the longitudinal axis of the motor vehicle, to control the driving direction of the motor vehicle Note: Components such as steering knuckle and kingpin are covered. 3.1.1.5 energy supply equipment equipment in steering system that is used to provide energy, control energy distribution and store energy Note: It includes storage reservoir, pipeline, wiring harness and medium, but excludes the engine (except the engine supplying energy to the power assisted steering system) and the driving of the engine to the energy source. 3.1.1.5.1 energy source component that provides energy in the required form 3.1.1.5.2 energy reservoir component of the energy supply equipment that stores the energy Example: pressurizable hydraulic accumulator or vehicle battery. 3.1.1.5.3 storage reservoir component for storing working medium with internal pressure at normal pressure Example: Steering oil tank. 3.1.2 Steering parameters 3.1.2.1 steering control force force acting on steering control equipment for vehicle steering 3.1.2.2 steering time time required from the start of the steering control equipment to the moment when the steered wheel reaches the specific steering angle 3.1.2.3 steering angle intersection angle formed by the intersecting line of the longitudinal center symmetry plane of the wheel and the ground and the projection of the longitudinal axis of the vehicle on the ground during steering 3.1.2.4 steering force all forces transmitted through the steering transmission equipment to drive the steered wheels to rotate 3.1.2.5 turning circle maximum circle projected by all points on the vehicle (excluding the external indirect vision equipment and the front direction-indicator lamp) on the ground plane when the vehicle travels in a circle 3.1.2.6 nominal radius of steering control minimum dimension from the rotation center to the rim of steering disc during steered wheel control, or distance from the rotation center to the steering control force application point (if multiple application points are available, the point with the maximum force shall be taken) if other control forms are adopted 3.1.3 Types of steering systems 3.1.3.1 Motor vehicles 3.1.3.1.1 main steering equipment equipment in the steering system that mainly determines the driving direction of a vehicle Note 1: Main steering equipment generally includes three forms: manual steering, power assisted steering, and full-power steering. Note 2: Manual steering refers to that the steering force only comes from the steering control force provided by the driver. 3.1.3.1.1.1 power assisted steering equipment of which the steering force comes from the steering control force provided by the driver and one or more energy supply equipment, including the equipment of which the steering force is only provided by one or more energy supply equipment when the steering system is in good condition, and may still be provided by the driver manually when the steering system (with power assisted equipment) is in fault condition, to complete the steering action 3.1.3.1.1.2 full-power steering equipment of which the steering force is completely provided by one or more energy supply components 3.1.3.1.2 self-tracking steering equipment equipment that changes the steering angle of one or more non-steered wheels only when the wheels are subjected to forces and/or moments from the ground 3.1.3.1.3 auxiliary steering equipment; ASE equipment added on categories M and N vehicles that makes the steered wheels and/or wheels (front and/or rear) on other axles adjust the same or opposite steering angles in addition to the steering angle provided by the main steering equipment for adjusting the steering quality 3.1.3.2 Trailer 3.1.3.2.1 trailers self-tracking steering equipment equipment for changing the steering angle of one or more wheels only when the wheels of the trailer are subjected to a force and/or moment from the ground 3.1.3.2.2 additional steering equipment equipment independent of the main steering equipment of the tractor, which selectively adjusts the steering angle of one or more axles of a trailer according to different control purposes Note 1: Trailer steering system generally includes trailers self-tracking steering equipment, articulated steering, self steering, additional steering equipment, trailer full-power steering equipment, etc. Note 2: Articulated steering refers to the equipment by which the steering motion forms a relative angle between the longitudinal axis of the tractor and the trailer through the articulating mechanism of the tractor and the trailer, to change the driving direction of the tractor and generate steering force while the vehicle is running. Note 3: Self-steering refers to the equipment that changes the driving direction of the tractor through the angle formed by the longitudinal axis of the trailer frame (or the substitute load) and the longitudinal axes of the tow bar (and turntable frame) and generates steering force while the vehicle is running. Note 4: Trailers full-power steering equipment refers to the equipment by which the steering force is provided entirely by one or more energy-supplying components. 3.1.4 Types of steering transmissions 3.1.4.1 purely mechanical steering transmission operation in which the steering force is purely transmitted by the mechanical mechanism 3.1.4.2 purely hydraulic steering transmission operation in which the steering force is purely transmitted by hydraulic pressure at least in one transmission link 3.1.4.3 purely electric steering transmission operation in which the steering force is purely transmitted by electric power in at least one transmission link Note 1: The forms of steering transmission generally include mechanical steering transmission, hydraulic steering transmission, electric steering transmission, hybrid steering transmission, etc. Note 2: Hybrid steering transmission means that part of the steering force is transmitted by one mode in 3.1.4.1, 3.1.4.2 and 3.1.4.3, while the other part is transmitted by another mode. If the mechanical part used for transmission is only to provide the driver with a road feel, and the steering force transmitted by it is negligible for the whole system, it is regarded as a hydraulic or electric steering transmission. 3.2 Functional safety terms 3.2.1 safety concept safety measures designed during the system design which are taken to ensure that the system can still operate safely under fault and non-fault conditions, not causing unreasonable safety risks to vehicle occupants and other road users Note: Providing some functionality or switching to a backup system may be part of the security concept. 3.2.2 unit smallest division of system components that can be combined to form a separate identifiable, analyzable or replaceable entity 3.2.3 electronic control system combination of a series of units that collaboratively realize vehicle control functions by means of electronic data processing Note: The system is usually controlled by software, and consists of independent functional components such as sensors, controllers and actuators, which are connected by transmission links. The system may include mechanical, electronic-pneumatic and electronic-hydraulic units. 3.2.4 transmission links means of interconnecting internal units for signal transmission, operational data transfer, or energy supply Note: They are usually electronic, or mechanical, pneumatic, or hydraulic. 3.2.5 safety metric quantified value of specific technical parameters given to meet safety goals 3.3 Other terms 3.3.1 electrical storage device device or combination of devices capable of storing electrical energy and supplying it to the transmission device of the full-power steering system Note: Multiple electrical storage devices connected in series and/or parallel to supply energy to a steering circuit are considered as one electrical storage device. Electrical storage device is an energy reservoir. 3.3.2 performance of an electrical storage device capability of a fully charged electrical storage device to supply power (W) and energy (Wh) 3.3.3 state of an electrical storage device current capability of an electrical storage device to supply power (W) and energy (Wh) 3.3.4 effect of ageing irreversible degradation in the performance of an electrical storage device caused by factors such as time, usage, and environmental conditions 3.3.5 energy management system system that monitors key variables affecting the performance and state of an electrical storage device (e.g., voltage, temperature, internal resistance, effect of ageing, SOC, power consumption, and charging cycles) and infers whether the actual capability of the electrical storage device meets the performance requirements specified in this document Note: Energy management system is not necessarily part of the full-power steering system. 3.3.6 electrical supply device that supplies electrical energy to the electrical storage device of the steering system Example: Batteries, rechargeable energy storage systems (REESS), generators, fuel cells, or combinations thereof.