S7 New Model Technical Training-Global -5 Chassis System (1)

1.

声明
• 课件内容仅做售后培训用途
• 所列明的配置信息只为讲解相关技术 不代表实车配置
• 所有技术维修工艺及参数请严格参考维修手册执行
DISCLAIMER
• The content below is for after-sales training only.
• The configuration information listed is only for explaining the relevant technology,
instead of representing the actual vehicle configuration.
• All technical maintenance processes and parameters shall be strictly
implemented in accordance with the maintenance manual.

2.

S7 New Model Technical Training
- Chassis System
After-sales Technical Training of GAC International
August 20, 2025

3.

Contents
1
Suspension and Positioning
2
Electric Power Steering
3
Integrated Braking
4
TPMS Tyre Pressure Monitoring
3

4.

Learning Objectives
Upon completion of this section, trainees should be able to:
◼ Master the wheel alignment adjustment methods for the S7 vehicle;
◼ Understand the features of the S7 Electrical Power Steering (EPS) system;
◼ Master the working principle of the S7 integrated braking system;
◼ Master the working principle and calibration method of the S7 TPMS.
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5.

Contents
1
Suspension and Positioning
◼ System Overview
◼ Positioning Parameters
◼ Suspension Adjustment
5
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6.

System Overview
◼ Suspension Function
The suspension system refers to the entire support system composed of springs and shock absorbers between the
vehicle body and the tires. Its function is to transmit torque between the wheels and the frame, cushion the impact force
transferred from the road to the frame or body, attenuate the resultant vehicle body vibrations, and improve ride comfort.
Suspension
Front
Suspension
Rear
Suspension
Name
Composition
Features
MacPherson
Independent
Suspension
Front stabilizer bar assembly, front stabilizer
link assembly, front lower control arm
assembly, front subframe assembly, front
knuckle, front strut assembly.
Good responsiveness and
handling, simple and
compact structure, minimal
space usage, low cost,
and light weight.
Multi-link
Independent
Suspension
Rear stabilizer bar assembly, rear stabilizer
link assembly, rear toe control arm assembly,
rear trailing arm assembly, rear upper control
arm assembly, rear lower control arm
assembly, rear knuckle assembly, rear strut
assembly, rear coil spring, rear subframe
assembly.
Superior comfort
Good tire grip
Excellent handling stability
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7.

System Overview
◼ Front Suspension
Right front strut
assembly
Front stabilizer
link assembly
Front stabilizer bar
assembly
Left front strut
assembly
Right front lower
control arm assembly
Left front lower control
arm assembly
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8.

System Overview
◼ Rear Suspension
Rear upper arm
assembly
Rear shock
absorber assembly
Left rear trailing arm
assembly
Left rear stabilizer
link assembly
Rear subframe
assembly
Right rear trailing
arm assembly
Rear stabilizer bar
assembly
Rear toe control
arm assembly
Rear lower arm
assembly
Right rear stabilizer link
assembly
Rear coil
spring
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9.

Positioning Parameters
◼ Four-wheel Alignment Parameters
Item
Parameters
Front wheel toe-in
5′±3′
Front wheel camber
-17′±45′
King pin caster angle
5°27′±45′
Kingpin inclination ANGLE
12°42′
Rear Wheel Toe-in
6′±3′
Rear wheel camber
-1°±45′
Front wheel
Rear wheel
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10.

Suspension Adjustment
◼ Wheel alignment adjustment must be carried out under the following conditions:
– Driving performance defects;
– Damage caused by an accident and replacement
of related parts;
– Suspension-related parts removed or replaced;
– Uneven tire wear or vehicle pulling to one side.
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11.

Suspension Adjustment
◼ Front Suspension
The front wheels can only be adjusted for toe-in value. Loosen the left and right adjustment nuts, make the adjustment
according to the instructions on the wheel alignment machine, and tighten the adjustment nuts after completion.
Front wheel toe-in adjustment nut
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12.

Suspension Adjustment
◼
Rear Suspension
For the S7 model, the adjustable rear wheel alignment parameters are rear toe and rear camber. Each can be adjusted via its corresponding
eccentric nut.
Adjustment method: First loosen the lock nut from the front side, then use the appropriate tool to adjust the eccentric nut from the rear side.
Continue adjustment until the suspension alignment parameter reaches the specified value.
Rear Wheel Toe-in
Adjustment Eccentric Nut
Rear Wheel Camber Adjustment
Eccentric Nut
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13.

Contents
2
Electric Power Steering
◼ System Overview
◼ Control Principle
◼ Maintenance Precautions
13
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14.

System Overview
◼ Basic Components
The Electric Power Steering (EPS) system is a
power steering system that directly relies on an
Reduction
mechanism
electric motor to provide assist torque. It mainly
consists of an integrated Torque Angle Sensor
(TAS), a motor, an Electric Steering ECU, and a
TAS
reduction mechanism.
The S7 adopts a DP-EPS dual pinion structure for
ECU
Motor
higher steering precision.
DP-EPS
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15.

Control Principle
◼ Working Principle
The electric steering ECU detects the driver’s
To the Power
Supply
CCU
EPS
steering torque input and monitors vehicle signals
IG1 power
supply
such as speed and engine speed. Based on these
inputs, it controls the motor’s assist torque in real
time to deliver optimal steering assistance. This
ensures light steering effort at low speeds and
stable steering at high speeds, thereby improving
CCU
ZCU-L
To the Power
Supply
driving comfort and vehicle safety
To the Power
Supply
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16.

Maintenance Precautions
After performing a wheel alignment or replacing the ESP unit on the vehicle, the steering wheel center position may be
affected. It is necessary to recalibrate the midpoint of the EPS TAS using a diagnostic scan tool.
Locate the "TAS Zero-Point
Calibration" routine in the
general/standard routines menu
and follow the system prompts
to perform the operation.
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17.

Contents
3
Integrated Braking
◼ System Overview
◼ Control Principle
◼ Self-diagnosis
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18.

System Overview
◼ Basic Functions
The S7 model adopts Bosch’s IPB system, which eliminates the vacuum booster and instead uses an electric motor for
assist, forming a highly integrated decoupled electro-hydraulic braking system. The IPB system mainly integrates the
following functions:
Anti-lock braking system (ABS)
Electronic stability program (ESP)
Hill hold control (HHC)
Hydraulic brake assist (HBA)
Traction control system (TCS)
Electronic braking force distribution (EBD)
Comfort stop technology (CST)
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19.

System Overview
◼ System Composition
The integrated braking system primarily consists of
an integrated brake control unit, a brake fluid
Direct-insertion
wheel speed sensor
reservoir assembly, four wheel cylinders, and four
direct-insertion wheel speed sensors.
Direct-insertion
wheel speed sensor
Direct-insertion
wheel speed sensor
Reservoir connecting
hose
Integrated Power Brake
(IPB) system
Brake fluid reservoir
assembly
Direct-insertion
wheel speed sensor
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20.

Control Principle
To the Power
Supply
IG1 power
supply
Supply
To the Power
Supply
Front zonal control
unit
To the Power
Right front wheel
speed sensor
Supply
Left rear wheel speed
sensor
sensor
Left front wheel speed
To the Power
Right rear wheel speed
sensor
To Central
Processing Unit
Integrated Power Brake (IPB) system
◼ Control Principle Diagram
Brake fluid
level sensor
To Central Processing Unit
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21.

Control Principle
◼ IPB Hydraulic Control Schematic Diagram
Name
Description
SSV
Simulator separation valve
PSV
Plunger separation valve
CSV
Circuit separation valve
TSV
Test separation valve
MC2
Main cylinder circuit 2 of
pressure sensor
PS
Pressure sensor
APM
Motor
ASP
Plunger
PFS
Pedal feeling simulator
PTS
Pedal travel sensor
RPS
Rotor position sensor
MCS
Motor current sensor
PRV
Pressure heavy-duty valve
IV
Oil inlet valve
OV
oil outlet valve
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22.

Control Principle
◼ Braking - Normal Mode
The ECU controls the motor operation based
on the signals from PTS and MC2, and the
movement of the plunger generates liquid
pressure.
CSV1 valve
OFF
CSV2 valve
OFF
SSV valve
ON
PSV1 valve
ON
PSV2 valve
ON
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23.

Control Principle
◼ Braking - Fault Mode
Under unreliable signal conditions or power
failure, the solenoid valve is in its initial state,
resulting in a loss of motor-assisted braking
force and altered the brake pedal feeling.
CSV1 valve
ON
CSV2 valve
ON
SSV valve
OFF
PSV1 valve
OFF
PSV2 valve
OFF
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24.

Self-diagnosis
◼ Leakage and Air Detection Procedure
The routine inspection procedure operates when the
ignition switch is turned on or off.
The test separation valve (TSV) operates to separate the
brake fluid reservoir.
The motor (APM) and plunger (ASP) generate pressure in
the Tandem brake master cylinder.
If a pressure leak is detected, a fault code will be recorded.
CSV1 valve
ON
CSV2 valve
ON
SSV valve
OFF
PSV1 valve
OFF/ON
PSV2 valve
OFF/ON
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25.

Contents
4
TPMS Tyre Pressure Monitoring
◼ System Overview
◼ Working Principle
◼ Control Logic
◼ Warning description
25
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26.

System Overview
◼ System Composition
Tyre pressure sensor: installed inside each wheel to monitor tyre pressure and temperature.
Radio Frequency Receiver (RFR) Module: Receives wireless radio frequency signals from the tire pressure sensors. It
is located inside the right-side D-pillar trim panel.
Central computing unit (CCU): decodes and processes signals received by the RFR, and transmits data to the
instrument pack via CAN bus.
Instrument pack control module (IP): displays current tyre pressure and temperature information, and issues an alarm
signal when abnormalities occur.
RFR
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27.

Working Principle
◼
Basic Principle
The tyre pressure sensors transmit tyre pressure and temperature data to the RFR via wireless RF signals.
The RFR transmits the received RF signals to the CCU via the CAN bus.
The CCU decodes and processes the received CAN signals, then transmits them via the CAN bus to the instrument pack to
display current tyre pressure and temperature information.
When the tyre pressure is abnormally low or high, or experiences rapid air leakage, or overheats, the CCU triggers an alarm
signal and the tyre pressure fault light turns on.
If the TPMS system has a fault, the CCU will issue an alarm signal, causing the tyre pressure fault light to flash for 60 seconds
before remaining illuminated.
Tyre pressure monitoring system (TPMS): The tyre pressure sensor monitors tire pressure and temperature, and displays the
readings on the instrument pack.
Tire pressure sensor replacement or tire rotation: The TPMS will automatically complete the learning and calibration process
over the course of the next few driving cycles.
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28.

Control Logic
Left front tyre
pressure sensor
Right front tyre
pressure sensor
Left rear tyre
pressure sensor
ZR_CANFD3
RFR
RF
Receiver
Module
Tyre pressure and
temperature
information
IDC_CANFD
CZR_CANFD
ZCU_R
Right zonal
module
Tyre
pressure and
temperature
information
CCU
Central
control
module
Instrument
Cluster
Module
Right rear tyre
pressure sensor
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29.

Warning description
◼
TPMS Alarm
If the vehicle remains stationary for over 7 days or the battery is disconnected, the pressure and temperature values displayed on the
IPCM will show "--" upon power-up. After driving at speeds exceeding 25 km/h for several minutes, the current tyre pressure and
temperature values will appear on the IPCM. When the tyre pressure (cold pressure) is inflated to the recommended cold pressure of
250 Kpa, the fault is cleared and the tyre pressure fault light turns off.
Alarm Conditions
High-voltage
When tyre pressure exceeds 330 Kpa, the tyre pressure monitoring system indicator turns on.
When the tyre pressure value is below 300 Kpa, the fault is cleared and the tyre pressure fault light turns off.
When the tyre pressure falls below 75% of the recommended cold tyre pressure, the tyre pressure monitoring
Low-pressure
system indicator turns on.
When the tyre pressure (cold pressure) is inflated to the recommended cold pressure, the fault is cleared and
the tyre pressure fault light turns off.
High temperature
When the tyre temperature exceeds 85℃, the tyre pressure monitoring system indicator turns on.
When the tyre temperature drops to 80℃, The fault is cleared and the tyre pressure fault light turns off.
When the tyre pressure decreases continuously at a rate exceeding 30 Kpa/minute for over 1 minute, the tyre
Rapid air leakage
pressure monitoring system indicator turns on.
When the ignition switch is powered on or the tyre air leakge is resolved, the fault will be eliminated and the
fault light turns off.
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Thank You for Watching