Chery QQ6 (S21) / S12LHD. Manual — part 119

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CONTENT

Common Abbreviations and Acronyms in This Manual. . . . . . … 2

I. Product Instruction. . . . . . . . . . . . . …. 3

1． ABS Overview . . . . . . . . . . . . . ….. 3

1.1 System Function. . . . . . . . . . . . . 3

1.2 Comparison between with and without ABS braking effects. . . …... 3

2． System Structure. . . . . . . . . . . . . .. 5

3． System Functioning Theory. . . . . . . . . . . . 6

3.1 ABS Control Theory. . . . . . . . . . . . … 6

3.2 ABS Control Mode. . . . . . . . . . . . .. 6

3.3 EBD Control Mode. . . . . . . . . . . . .. 9

II. Removal and Installation. . . . . . . . . . . . ... 10

1． Spare Part Supply Status. . . …. . . . . . . …. 10

2． Notices for Removal and Installation. . . . . . . . . . 10

3． HECU Replacement. . . . . . . . . . . . …. 12

III. Trouble Diagnosis and Troubleshooting. . . . . . . . . . 14

1． Checking Sequence. . . . . . . . . . . . … 14

2． Common Trouble Diagnosis and Troubleshooting of MGH-25 ABS. . … 14

2.1 Checking of ABS and EBD Warning Lamp. . . . ...….. . ... 14

2.2 Table for Common Troubles. . . . .. . . . . . .. 14

2.3 Trouble Code Readout and Deletion without Trouble Diagnosis Instrument… 15

2.4 Trouble Checklist of Trouble Code. . . . . . . . . 17

2.5 Trouble Checklist without Trouble Code. . . …. . . . 25

IV. Air Discharge and Oil Refill. . . . . …. . . . . ….. 30

1. Regular Operation Procedure. . . . . . . . . . …. 30

2. Checking Device. . . . . . . . . . . . . … 30

3. Notices for Air Discharge and Oil Refill. . . . . . . . . … 30

4. Determination Method for Vehicles with Air Discharge Trouble. . . . .. 31

5. Measures in Event of Troubles during Air Discharge and Oil Refill

(for internal dry status of brake system). . . . . . . . . … 31

6.

Measures in Event of Trouble during Checking and ABS Functioning Test

(for internal wet status of brake system) . . . . . . . . . 32

Annex I Malfunction Cases and Incorrect Repair Cases. . . . . ….. 34

Annex II ABS Basics. . . . . . . . . . . …... ... 36

Annex III ABS Internal hydraulic Flow Diagram. . . . . . ….… 37

Annex IV Connector Pin Layout of MGH-25 ABS ECU. . . .. . .… 37

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Common Abbreviations and Acronyms in This Manual

FL——Front Left

FR——Front Right

RL——Rear Left

RR——Rear Right

ABS——Anti-lock Brake System

EBD——Electronic Brake Distribution

ECU——Electronic Control Unit

HU、HCU——Hydraulic (Control) Unit

HECU——ECU+HCU

LPA——Low Pressure Accumulator

MCP——Master Cylinder Primary, one of two outlet of master cylinder. P refers to

primary.

MCS——Master Cylinder Secondary, one of two outlet of master cylinder. S refers to

secondary

SDL——Serial Data Link

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I. Product Instruction

1． ABS Overview

1.1 System Function

① Promotion of vehicle stability;

Guarantee of vehicle steering ability;

②

Guarantee of shortest brake distance.

③

1.2 Comparison between with and without ABS braking effects

Braking on Bisectional Roads (Split)

Evading the obstacles during braking

Without ABS

With ABS

Without ABS

With ABS

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1.3 Tire Dynamic Characteristics

Slip Ratio

Brake Force

Steering Force

Slip Rate [%]