Chery S21 2007 2016 User Manual

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Mando MGHAnti-Lock Brake

System

User’s Manual

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

Page 1 of 38

Common Abbreviations and Acronyms in This Manual

FL——Front Left

FR——Front Right

——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

Page 2 of 38

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

Without ABS

With ABS

Braking on Bisectional Roads (Split)

Without ABS

With ABS

Evading the obstacles during braking

Page 3 of 38

Brake Force

1.3 Tire Dynamic Characteristics

Slip Ratio

Steering Force

Slip Rate [%]

Page 4 of 38

2． System Structure

Motor

Including:

Electronic Control Unit

Hydraulic Unit

Sensor

Motor

The sensor will calculate the speed and acceleration/deceleration of four wheels and judge the skid status of the wheels and therefore drive the electromagnetic valve and motor, control the pressure increment and pressure reduction, maintain the status, and etc. The basic hydraulic circuit is comprised of the 1st circuit and the 2nd circuit that is active only when the ABS is functioning and is the integral part that controls the hydraulic parts transmitted to various wheels. Depending on the transmitted signal output of the sensor, the ECU performs the calculation and judges the skid status to determine if it’s necessary to run the ABS. Therefore, depending on the control procedure of the ECU, the electromagnetic valve and the motor will be started to control the pressure increment and pressure reduction, maintain the status, and etc. In order to make the ECU to calculate the speed and acceleration/ deceleration of the four wheels, it always transmits the revolution measurement of the gear ring to the ECU. When the ABS is functioning, the motor will rotate following the ECU signal and convert the rotation movement into linear reciprocated movement via the bearing to circulate the brake oil.

Page 5 of 38

3． System Functioning Theory

Start

Reduction

)

ta tus that the wheels

3.1 ABS Control Theory

ABS Control Range

Start Pressure Increment

λ= 0%: The status that the brake is

not functioning

Pressure

Skid Ratio

λ= 100%:

Slip Ratio

Body Speed – Wheel Speed

Body Speed

Tire braking force (µs)

Tire transversal friction force (µs

The s

are lock ed

3.2 ABS Control Mode

① Functioning Status of General Brake

For the vehicles equipped with ABS, if the braking pressure applied onto the wheels is not enough to lock the wheels, the pressure generated by the general pump will transmit to the wheel branch pump via the normal open valve to obtain the braking effects. When it’s unnecessary for further braking, the driver will reduce the pressure on the brake pedal and then the brake liquid of various wheels will return to the general pump to reduce the braking pressure.

Solenoid Valve Power Status Solenoid Valve Status Normal Open Valve (NO Valve) OFF Open Normal Close Valve (NC Valve) OFF Close

Page 6 of 38

ABS ② Functioning (Pressure Reduction) Status

For the vehicles equipped with ABS, if the applied braking pressure is too big, the wheels will have rapider deceleration than that of vehicle body, which will be ready to result the lock of the wheels. Under such case, the ECU will transmit the code for wheel pressure reduction to the HCU, namely turn off the normal open valve and turn on the normal close valve to reduce the pressure of wheel branch pump. In such case, the brake oil released by the wheel branch pump is temporarily stored in the low pressure accumulator (LPA). The brake oil stored in the LPA will be sucked back to the general pump by the oil pump started following the rotation of the motor. The brake liquid will return to the high pressure accumulator (HPA) in the pipeline and reduce the high pressure pulse generated by the running of the oil pump by means of the orifice hydraulic resistance.

Solenoid Valve

Power Status

Solenoid Valve Status Normal Open Valve (NO Valve) ON Close Normal Close Valve (NC Valve) ON Open

ABS ③ Functioning (Maintaining) Status

When the branch pumps of the wheels are applied with proper pressure via the pressure reduction or pressure increment, the normal open valve and the normal close valve will be turned off to maintain the pressure of the wheel branch pumps. For the operations mentioned in above ~ ②④, depending on that wheels are locked or not, the ABS will function till the vehicle is fully stopped and therefore the safety and steering capability of the vehicle are guaranteed.

Solenoid Valve Power Status Solenoid Valve Status Normal Open Valve (NO Valve) ON Close Normal Close Valve (NC Valve) OFF Close

Page 7 of 38

ABS ④ Functioning (Pressure Increment) Status

During the implementation of the pressure reduction, if the excessive brake liquid is drained or the friction coefficient between the wheels and the road is increased, it’s necessary to increase the pressure of various wheels. Under such case, the ECU will transmit the code for wheel pressure increment to the HCU, namely turn on the normal open valve and turn off the normal close valve to increase the pressure of wheel branch pump. During the implementation of the pressure reduction, the brake liquid stored in the low pressure accumulator (LPA) will continue to rotate the motor to drain the brake liquid under the pressure increment status. In such case, the brake liquid is supplied to branch pump of various wheels via the general pump and normal open valve. The brake liquid will return to the high pressure accumulator (HPA) in the pipeline and reduce the high pressure pulse generated by the running of the oil pump by means of the orifice hydraulic resistance.

Solenoid Valve Power Status Solenoid Valve Status Normal Open Valve (NO Valve) OFF Open Normal Close Valve (NC Valve) OFF Close

Page 8 of 38

3.3 EBD Control Mode

In order to guarantee the operation stability, the EBD function is designed in such manner that front wheels are stopped ahead of the rear wheels. As the front brakes undertake more works than that of the rear brakes, it will cause that the rear wheels will be stopped firstly when apply with same braking pressure. In order to preventing the occurrence of above thing, a device to reduce the braking pressure applied on the rear wheels under certain pressure is required, of which this function is fulfilled by the pressure reducing valve (P-Valve). The special pressure reducing valve is not required for the vehicles equipped with ABS as the procedure supplemented to the ABS will fulfill the control function on the braking pressure of the rear wheels so as to effect the improvement of vehicle operation stability.

Page 9 of 38

II. Removal and Installation

1. Spare Part Supply Status

① Differentiation between Dry Type HECU and Wet Type HECU

The biggest differentiation between the dry type HECU and wet type HECU is that the no air discharge is conducted in the 2nd circuit (namely the circuit from the normal close valve to the general pump) of the dry type HECU. Therefore, when the spare part is of wet type HECU, it’s only necessary to conduct the air discharge and oil refill in accordance with the regular brake system after the replacement. When the spare part is of dry type HECU, besides that the air discharge and oil refill are required in accordance with the regular brake system after the replacement, it’s necessary to conduct the air discharge and oil refill to the 2nd circuit of the HECU. In addition, for the appearance, the wet type HECU has the bolts for sealing purpose and the dry type HECU has the protection film. The product label located on the motor is marked with the part number of the products, through which the dry type HECU and wet type HECU can be differentiated. Take the S21 model for instance, the dry type Mando product number is BH601-086-00 and the wet type Mando product number is BH602-386-00.

Dry Type Wet Type

② Notices

If the bolts on the wet type HECU are fallen off (such as during the transportation), besides that the air discharge and oil refill must be conducted for 1st circuit, maybe it’s necessary to conduct the air discharge and oil refill to the 2nd circuit.

2． Notices for Removal and Installation

① Notices for HECU Assembling

During the assembling of brake pipeline:

Remove the protection film attached onto the HECU

before the operation.

Confirm the pipeline of general pump and wheel branch

pump before the operation.

(General pump: MCP, MCS Wheel branch pump: FR, FL, RR, RL)

Confirm if the brake hose is tightened to 120~160

kgf·cm with special tool or torque wrench.

Notice to keep away the impurity ingress into the

HECU hole and brake hose during operation.

Page 10 of 38

② Notices for HECU Bracket Assembling

Bracket

During the assembling of HECU bracket:

During the tightening of the bolt (3

pcs), it may cause the incorrect assembling due to the friction resistance of the cushion pad. It’s

Installation bolt

preferable to use the lubricating oil with the physical properties that will not impair the cushion pad.

Bumper block

Insert the bolts (3 pcs) onto the

cushion pad installed onto the bracket before install to the HECU, which will help the operation.

Confirm if the bolts (3 pcs) are tightened to 80~100 kgf·cm with special tool or torque

wrench.

③ Notices for Installation of HECU and Bracket Assembly

During the installation to vehicle body:

Attach the components of brake hose and

bracket to the HECU and install to the vehicle body with the body fixing bolts.

Confirm if the body fixing bolts are

tightened to 190~260 kgf·cm with special tool or torque wrench.

Again confirm if the pipeline installation

of general pump and wheel branch pump is correct.

(General pump: MCP, MCS; Wheel branch pump: FR, FL, RR, RL)

Tighten th e brake hose not full y tighte ned to the specified torque (120 ~ 160

kgf· cm) with special tool or torque wrench.

④ Other Notices

Find out the trouble cause with diagnosis instrument before repair.

The package of the spare parts should be unwrapped only before the installation.

Only use the parts supplied by the original manufacturer.

Notice the cleanliness during removal and only use the non-fuzz cloth for cleaning.

Use the detergent not containing the mineral oil to clean the appearance before removal.

Do not use the compressed air or move the vehicle when the system is opened.

After the removal of the ABS assembly, plug various hydraulic outlets with plugs as soon as

possible.

Remove other components interfering the operation.

Use DOT#3 brake liquid.

Immerse the seals with brake liquid, instead of engine oil or braking ointment.

Check all hydraulic connectors for leakage.

Page 11 of 38

3． HECU Replacement

① When the vehicle is stopped, remove the 25-pin connector and harness wiring of the HECU

located within the engine compartment.

25-Pin Connector Used in MGH-25 ABS

(P/No：AMP 368482-1)

② Screw off in counter clockwise direction the 6 bolts (M10x1.0) connected to the HECU brake

hose with 11mm tool (wrench) (rotate in clockwise direction during refit). The tightening torque for the brake hose is 120 ~ 160 kgf·cm.

③ Screw off in counter clockwise direction the 3 bolts or nuts connected to the bracket with

12mm tool (wrench) (rotate in clockwise direction during refit). The tightening torque for the fixing bolts or nuts of the bracket is 190 ~ 260 kgf·cm.

④ After the removal of the product, screw off in counter clockwise direction the 3 embedded

bolts (M6x1.0) attached to the HECU with 5mm tool (hex wrench) (see the figure in next page).

Page 12 of 38

⑤ Screw off in counter clockwise direction the 6 bolts from the after-service HECU with 6mm

tool (hex wrench).

⑥ Screw on in clockwise direction 3 embedded bolts to assemble the after-service HECU and

the bracket with 5mm tool (hex wrench). The tightening torque for the embedded bolts is 80 ~ 100 kgf·cm.

⑦ With reference to above item ~ ①③, install the replacement after-service HECU to the

vehicle in reverse order.

Page 13 of 38

Checking of wheel

ECU ID determination

hecking of valve

and terminal

Record checking

Sensor air gap determination

Trouble code

Valve status determination

•Pipeline assembling status

III. Trouble Diagnosis and Troubleshooting

1． Checking Sequence

Regular checking

•

• ECU trouble code

determination

• Warning lamp status

determination

speed sensor

•

• Sensor assembling status

determination

•

determination

result

•

determination

• Trouble code record

．

Trouble Diagnosis and Troubleshooting of MGH-25 ABS

2.1 Checking of ABS and EBD Warning Lamp

Check if the ABS and EBD warning lamps are illuminated in accordance with following: ① Rotate the vehicle key to turn on the power. The ABS warning lamp will illuminate and then go off in 3s. ② It indicates the trouble if the status mentioned in ① is not present and it’s necessary to check the trouble code with reference to the trouble code checklist. ③ If the warning lamps are completely not illuminated, please refer to the trouble checklist without trouble code.

2.2 Table for Common Troubles

Position Cause Structure

Warning lamp

ABS EBD

Vehicle harness

Incorrect assembling of

brake hose

Brake oil leakage Poor start of ABS and EBD

Incorrect wiring

installation

Locked wheels and brake off-

tracking

Off Off

Brake failure

Air discharge trouble Deteriorated ABS performance

Motor Motor trouble ABS start failure On Off

ECU

Trouble of ECU power line

Trouble of valve power

line

Poor grounding of ECU Start failure of ABS and EBD

Start failure of ABS and EBD

On On

ECU trouble Start failure of ABS and EBD

Speed sensor

Trouble of motor wire line

Sensor open-circuit/short-

circuit

Gear ring trouble, sensor

interference trouble, air gap

trouble

In event of whichever trouble: ABS

In event of both troubles: Start failure

ABS start failure On Off

start failure

of ABS/EBD

In event of whichever trouble:

Incorrect start of ABS

of ABS/EBD

On Off

On On

On Off

On On

Page 14 of 38

2.3 Trouble Code Readout and Deletion without Trouble Diagnosis Instrument

① Purpose and condition of trouble code readout without trouble diagnosis instrument

If without the trouble diagnosis instrument, it may display the trouble status of the ABS via the ABS warning lamp and read out the trouble code to facilitate the trouble determination and troubleshooting. In such case, the trouble code will be displayed in 2-digit number. Please refer to the numbers in parentheses in the trouble checklist of trouble code in succeeding section 2.4.

The service conditions are as follows:

Vehicle speed below 2km/h; Without connection of trouble diagnosis instrument; The line L (namely the pin 7 of interior diagnosis socket) should be always grounded

during the diagnosis process.

In addition, at finish of the trouble code readout, restore the ECU status of the ABS to the normal mode (previously, it’s the diagnosis status), of which the method is as follows: At finish of the diagnosis operation, disconnect the grounding status of the line L, rotate the key to power off status, and then re-connect.

② Readout method of trouble code without trouble diagnosis instrument

Read out the trouble code in accordance with following procedure when the service conditions for trouble code readout without trouble diagnosis instrument are met:

Line L

Ignition

Switch

ABS

warning

lamp

The display will be repeated without any new trouble code.

The steps in above figure are respectively:

A. Rotate the vehicle key to power on position after the line L is grounded;

B. When the ABS warnin g lamp illumi nates and lasts for 3s, it indicates t he start of diagnosis;

C. When the ABS war ni ng lamp is off for 3s, it indic ates that it enters into the trouble code display phase;

D. Trouble code display and readout;

E. Wh en th e AB S wa r ni ng la mp is off fo r 3 s , it i n di c at e s th a t it ent er s in to ne xt tro u b le dis p l ay pha s e or circu l ated di s pl a y phas e ;

F. The display and readout of new trouble code and the circulated display of last trouble code.

Page 15 of 38

The meaning of symbols in the figure is as follows:

Line L

ithin

Ignition switch

Brake pedal

ABS warning lamp

3s Deletion period

3s Pedal depressing

Peda

l releasing

Within

(1 time)

ithin 2s

Within 2s

Code

The symbol for diagnosis start. The warning lamp starts flashing For differentiation of the duration of various trouble codes during the display of multi trouble codes Flashing interval of warning lamp at the presence of trouble code 0.5s

Symbol Description Duration

3.0s

For differentiation of the interval of various digits of trouble code

during the display of certain trouble code (for this interval, the first digit is for tens digit and the second digit is for ones digit)

1.5s

Take the process shown in above figure for instance. Within the display span of the first trouble code, before the presence of T4 (namely, 1.5s before the off of the warning lamp), since the warning lamp flashes twice (the duration for each on and off is both T3, namely 0.5s), the first digit of the 2-digit trouble code (tens digit) is at 2; after the presence of T4 (namely 1.5s after the off of the warning lamp), since the warning lamp flashes once, the second digit of the 2-digit trouble code (ones digit) is at 1. After that, the warning lamp will be off for 3s (namely T2 duration). Therefore, the display of first trouble code is completed with the trouble code of 21. The detailed description of the trouble is shown in the trouble code checklist in section 2.4. Also, the second trouble code of 22 can be obtained.

③ Deletion of trouble code without trouble diagnosis instrument

After the trouble code readout and troubleshooting based on the trouble code checklist, it’s necessary to delete the previous trouble code before the re-checking of the trouble code. The condition for trouble code deletion is same with that of the trouble code readout. The detailed operation method is as follows:

(2 times)

(3 times)

(4 times)

(5 times)

The steps in the above figure are respectively as follows:

A. After the brake pedal is depressed, ground the line L and rotate the vehicle key to the power on position; B. The ABS warning lamp illuminat ion and go off in 3 s; C. Start to release the p edal wi thin 1s after the ABS war ning lamp goes off; D. After the pedal is released for appr oximate 1s, re-dep ress the p edal for appr oximate 1s. Repeat the ab ove operation for 5 times. During this operation, the warni ng lamp will not b e illuminated; E. The ABS warning lamp illumi nates a nd lasts for 3s. During t his period, the trouble code within thi s process will be deleted.

At the finish of the trouble code deletion, restore the ECU status of the ABS to the normal mode,

Page 16 of 38

of which the operation method is same with that of the trouble code diagnosis.

Ignition

Switch

warning

In addition, when the ECU of the ABS has no trouble code, ground the line L and rotate the key to the power on position. The flashing of the ABS warning lamp is conducted in accordance with the type in following figure, of which the symbol meaning is same with the foregoing section.

Line L

ABS

lamp

2.4 Trouble Checklist of Trouble Code

① Contents of Trouble Code



Trouble

code

C1 200

(11)

Contents

Open-circuit/short-circuit of left front sensor

Trouble

code

C1 206

(31)

Contents

Open-circuit/short-circuit of left rear sensor

C1 201

C1 202

C1 203

C1 204

C1 205

C1 101

C1 102

C1 604

(12)

(13)

(21)

(22)

(23)

(51)

(52)

(53)

Interference of left front sensor or gear ring

Air gap error of left front sensor

Open-circuit/short-circuit of right front sensor

Interference of right front sensor or gear ring

Air gap error of right front sensor

Battery voltage too high (above 17V)

Battery voltage too low (below

9.4V)

Trouble of ECU internal circuit or electromagnetic valve coil

C1 207

(32)

C1 208

(33)

C1 209

(41)

C1 210

(42)

C1 211

(43)

C2 112

(54)

C2 402

(55)

Interference of left rear sensor or gear ring

Air gap error of left rear sensor

Open-circuit/short-circuit of right rear sensor

Interference of right rear sensor or gear ring

Air gap error of right rear sensor

Trouble of electromagnetic valve fuse or electromagnetic relay

Trouble of motor fuse or motor

Page 17 of 38

② Trouble checklist of trouble code

Remove the connector from the

harness and sensor, confirm t he

assembling status, and check t he

nnector

pins and correctly

Is powered on?

Replace sensor

Replace HECU

Is the problem

Determine and repair

wiring broken portion or

Determine i f t he t wo li nes between

r B

Trouble Code

C1 200(11) C1 203(21) C1 206(31) C1 209(41) Open-circuit/short-circuit of sensor: At shor t- c ircuit or op e n-circuit

Possible Case

of ba tter y ano de or cat hode of sens or.

Table 1 Note: If the malfunctions corresponding to more than 2 trouble codes can be determined, after the trouble codes are deleted (erasable trouble codes), drive the vehicle to above 40km/h to determine the malfunctions to that the trouble codes correspond and check in accordance with the registered trouble codes (determine the same one trouble code).

Troubleshooting Flow

pins for deviation

Is status good?

Yes

harness side pin A and connecto of sensor assembly are powered

Yes

still present?

Harness

Correct the co

assemble the connector

replace wiring

Sensor

Sensor Head

Yes

Page 18 of 38

Trouble Code C1 202(13) C1 205(23)

Replace sensor

Replace HECU

Is problem

Checking

Yes No

C1 208(33) C1 211(43)

Possible Case Air gap error:

Air gap too big or self short-circuit of sensor (resistance value at 0) that results no signal or the gear ring not properly installed.

Troubleshooting

Flow

Table 2

Note: ①The air gap refers to the gap between the gear ring and the sensor; ② If the malfunctions corresponding to more than 2 trouble codes can be determined, after the trouble codes are deleted (erasable trouble codes), drive the vehicle to above 40km/h to determine the malfunctions to that the trouble codes correspond and check in accordance with the registered trouble codes (determine the same one trouble code).

still present?

complete

Page 19 of 38

Trouble Code C1 201(12) C1 204(22)

Replace sensor

Replace HECU

Yes No

C1 207(32) C1 210(42)

Possible Cause Interference of gear ring or sensor:

Occurred when installed with nonstandard specification gear rings.

Troubleshooting

Flow

Table 3

Note: ① The sensor signal is not uniform when the gears are adhered with engine oil and the impurities such as slag; ② The air gap refers to the air gap between the gear ring and the sensor; ③ If the malfunctions corresponding to more than 2 trouble codes can be determined, after the trouble codes are deleted (erasable trouble codes), drive the vehicle to above 40km/h to determine the malfunctions to that the trouble codes correspond and check in accordance with the registered trouble codes (determine the same one trouble code).

Is problem

still present?

Checking complete

Page 20 of 38

Trouble

Yes Yes Yes Yes Yes Yes No No No No No No

Adjust connector pins

Correctly assemble

Replace HECU

Replace AC

Is below 9.4V?

Is above 17V?

Is status good?

Is between

Check and

Is below 1

Check and replace

Adjust s

tatus of

Measure the voltage

between battery terminal

(+) and (

Remove harness side

connector and measure the

voltage between pin 4 (+) and

) and between pin 4(+) and

) when the entire vehicle

circuits are on.

Measure the re

sistance

between the harness side

connector pin 4(+) and

Confirm the assembling

status a nd pin displ acement

of harness side connector pin

Confirm and check

grounding status of harness

Measure the voltage between

) and

)

when the entire vehicle

circuits are on.

Re-check from

Code

Possible

Cause

C1 101(51) C1 102(52)

Abnormal battery voltage: Occurred when the voltage is too high or too low

8(24(-

Table 4

Note: If the malfunctions corresponding to more than 2 trouble codes can be determined, after the trouble codes are deleted (erasable trouble codes), drive the vehicle to above 40km/h to determine the malfunctions to that the trouble codes correspond and check in accordance with the registered trouble codes (determine the same one trouble code).

9.4V~17V?

4, 8, and 24

①

connectors

battery

battery (+) terminal

side connector pin 8 (and 24 (+)

replace wiring

Troubleshooting Flow

grounding terminal

pin 4 (+) and 8(between pin 4(+) and 24(-

item ①

generator

Page 21 of 38

Trouble Code C2 402(55)

(1) After the harness side

connector is removed, confirm

if the harness side pin 25 and

connected

Yes Yes Yes Yes Yes No No No No No Is status good?

Is status good?

Is it on?

Replace HECU

Is fuse (30A)

Confirm if the valve fuse

(30A) in the fuse box is

Re-check from item

①

Is forced drive good?

Forced drive the HECU with

diagnosis instrument ( valve rel ay and

Adjust the connector pins and

Confirm the assembling status and

pin displace ment of pin 25 of

Check a nd replace the wiring of

Check and replace

the wiring of harness

side pin 25.

Confirm if the harness side

pin 25 and the terminal in the

fuse box are connected

Possible Cause Malfunction of motor fuse/motor

Troubleshooting

Flow

the grounding wire ar

Table 5

harness side pin 25

broken

normal?

harness side connector

motor start)

Check and replace the valve fuse

correctly assemble connector

Page 22 of 38

Trouble Code C2 112(54)

(1) After the h arness side

connector is removed, confirm

if the harness side pin 25 and

the grounding wire are

connected

Yes Yes Yes Yes Yes No No No No No Is status good?

Is it on?

Replace HECU

Is fuse (3

0A)

Confirm if the valve fuse

(30A) in the fuse box is

Re-check from item

①

Is forced drive good?

Forced drive the HECU with

diagnosis instrument (valve

Adjust the connector pins and

Confirm the assembling status and

pin displace ment of pin 25 of

Check and replace the valve

Check a nd replace the wiring of

Check and replace

the wiring of harness

side pin 25.

Confirm if the harness side

the

fuse box are connected

Possible Cause Malfunction of valve fuse and relay:

a) Broken of primary relay or fuse b) Short-circuit of primary relay

Troubleshooting

Flow

pin 25 and the terminal in

broken

Table 6

harness side pin 25

normal?

harness side connector

correctly assemble connector

relay and motor start)

fuse

Page 23 of 38

Trouble Code C1 604(53)

Yes No Replace HECU

Is i

t below 1

? Confirm and check the grounding

status between the harness side

) and 24(1)

Remove the harness side connector and measure

the resistance between t he harness side connector

ing wire and between the pin

Possible Cause Malfunction of ECU internal circuit

and valve coil

Troubleshooting

Flow

pin 8 ( -) and ground

24 (-) and grounding wire

Table 7

connector pin 8(grounding terminal.

Page 24 of 38

control

No No No No No No Yes Yes Yes Yes Yes Yes Short-circuit?

Replace bulb

Check if warning lamp

of ABS

harness and grounding

wire are disconnected

Replace

Repair

Yes Is it normal?

Is it normal?

Does ABS

Is bulb

Replace fuse

Check and replace the

wiring of harness side

Check and replace

warning lamp drive

Check wa

rning lamp power

circuit and grounding

Check if the ABS

warning lamp bulb is

Is fuse normal?

Is socket normal?

Check fuse

socket of fuse

After the harness side connector

circuit between the harness side

pin 16 and warning lamp drive

Remove the harness side

connector and check the ABS

warning lamp when the entire

2.5 Trouble Checklist without Trouble Code

Trouble

Evidence

The ABS warning lamp doesn’t illuminate when the engine is started

Possible Cause ● Burn of fuse

● Open-circuit of power line

Troubleshooting

Flow

Check ABS warning

lamp fuse in fuse box

box

Table 1

● Burn of ABS warning lamp bulb

● Damage of ABS warning lamp

Repair fuse socket

warning lamp

illuminate?

is removed, check for short

component

damaged?

power circuit

harness

pin 16

circuit connector

connector

component

Page 25 of 38

Yes Yes No No Replace HECU

Check and replace

component

Check and replace

wiring of harness side

pin 16

After the harness side connector is

removed, confirm if it 's powered

t he harness side pin 16 and

Connect the harness side pin 16 to

n the entire

vehicle circuits are on.

s it powered?

Is warning lamp off?

Trouble Evidence

The ABS warning lamp constantly illuminates after the vehicle start

Possible Cause ● Damage of ABS warning lamp control

● Open-circuit of ABS warning lamp control circuit

● ECU damage of ABS

Troubleshooting Flow

between warning lamp drive component.

Table 2

the grounding wire whe

warning lamp dri

Page 26 of 38

No No No No Yes Yes Yes Checking complete

Checking complete

Replace HECU or

connector

Replace sensor

Replace harness, connector or

HECU

Is problem

Is prob

lem

Is the sensor correctly

installed?

Re-install the sensor

Check if the ABS ECU

are normal

Trouble

Evidence

Abnormal functioning of ABS

Possible Cause ● Damage of sensor

● Improper installation of sensor

● Problem of sensor harness

● Impurity adherence on sensor

Troubleshooting

Flow

with correct method

still present?

Table 3

● Damage of gear ring

● Damage of wheel bearing

● HCU damage of ABS

● ECU damage of ABS

still present?

socket and connector

Page 27 of 38

No No No No Is it normal?

Yes Yes Yes Yes Is it normal?

Is it normal?

Re-conduct the air

discharge

Air discharge checking

Check handbrake regulator

Having leakage?

ghten pipe connector to

Trouble

Evidence

Brake pedal travel too long

Possible Cause ● Improper adjustment of handbrake

● Leakage of brake liquid

● Severe wearing of brake friction disc

● Leakage of normal close valve

● Air in the system

Troubleshooting

Flow

Check hydraulic pipe

connector for leakage

Check wearing of brake disc

Table 4

120~160kgf.cm

Replace brake disc

Replace handbrake regulator

Replace HECU

Page 28 of 38

No No No

Is it normal?

Yes Yes Yes Check and replace

Check and replace ABS

Check and replace

wiring of harness side

pin 7

Correctly install the

connector

Confirm the connection

between the diagnosis

or and

Is fuse (10A)

Confirm

if the ABS ECU

fuse (10A) in the fuse box

With

After the trouble number is

determined, take measures based

on the troubleshooting for

various tro

Correctly connect the harness

side connector and confirm

After the harness side conne ctor is

s powered

between the harness side pin 7 and

vehicle diagnosis

Trouble

Evidence

Without diagnosis code output (communication failure with trouble diagnosis instrument)

Possible Cause ● Problem of diagnosis instrument

● Burn of fuse

● Broken of diagnosis line or loosening of connector

● ECU damage of ABS

Troubleshooting

Flow

instrument connect vehicle diagnosis connector

removed, confirm if it’

connector pin 7

Is it powered?

Table 5

is burnt?

normal?

the communications.

communications?

ECU fuse

diagnosis instrument

Yes

uble numbers.

Page 29 of 38

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Chery S21 2007 2016 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual