Chery S11 / Chery QQ. Manual — part 34

Chery QQ Service Manual Chassis System

4、Too long for pedal travel

Possible cause

Check any leakage in system

·Fluid leak
·Valve leak
·Air in system
·Disc damage
·Bad manual brake

Abnormal

Normal

Abnormal

Normal

Normal

Abnormal

abnormal

Replace manual brake

abnormal

Re-exhaust

abnormal Replace HECU

5、Must step on pedal hard

Possible cause

Check booster or pedal travel with conventional

way

·Bad booster

·Bad valve

Normal

Check exhaust

Normal

Check valve leakage

Normal

Check valve

Check booster and pedal

travel

Check manual brake

Check disc

Check any leakage

Screw connector

Replace disc

Replace HECU

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Chery QQ Service Manual Chassis System

6、No DTC put out( cannot communicate with tester)

Possible cause

Open in ABS ECU source circuit or diagnosis

circuit

·Fuse burn out

·Diagnosis wire

loose or damage

·ABS ECU damage

·Tester problem

No

Yes

Fix tester and try

again

Can tester communicate with

other MK20 ABS ECU

Abnormal

Replace

Check ABS fuse

Norma

No

Abnormal

Yes

On

No

Fix diagnosis plug or harness

Any display on tester

Check source wire,

ground wire, and

connector

Check terminal is conducted

with diagnosis terminal
（MK20I/E : terminal 7）

Fix or

replace

Replace ABS ECU

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Chery QQ Service Manual Chassis System

8、ABS inspection

Terminal

Item

Key
position MK20I/E

Specifications Unit

Battery and motor
voltage

OFF

25-8

10.1-14.5

V

Battery and solenoid
voltage

↑

9-24

↑

V

Source isolation

↑

8-4

0.00-0.5

V

Ground isolation

↑

8-24

↑

V

Source

ON

8-4

10.0-14.5

V

OFF

Light off

ON

ECU not
connected

Light on

OFF

Light off

ABS light

ON

Connect ECU

Light on for 1.7
sec and off

Brake light pedal not
push down

ON

8-18

0.0-0.5

V

Brake light pedal
push down

ON

8-18

10.0-14.5

V

Front left sensor
resistance

OFF

1-2

1.0-1.3

KΩ

Front right sensor
resistance

OFF

19-20

1.0-1.3

KΩ

Rear left sensor
resistance

OFF

5-6

1.0-1.3

KΩ

Rear right sensor
resistance

OFF

22-23

1.0-1.3

KΩ

Front left sensor out
put voltage

OFF

1-2

3.4-14.8

mV/HZ

Front right sensor
resistance out put
voltage

OFF

19-20

3.4-14.8

mV/HZ

Front left sensor out
put voltage

OFF

5-6

>12.2

mV/HZ

Rear left sensor out
put voltage

OFF

22-23

>12.2

mV/HZ

Sensor out put

voltage ratio

Max peak voltage

≦ 2

Min peak voltage

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Chery QQ Service Manual Chassis System

9、Check ABS
（1） Check the out put voltage of speed sensor
1. Check if the clearance between speed sensor and teeth ring is satisfied with
specification.
2. Lift the wheel and release manual brake.
3. Remove ABS harness and measure the points of connector.
4. Run the wheel at speed of 1/2 RPM and measure the out put voltage.
MK20 I MK20 I/E
Front left wheel terminal 4 – 11 terminal 1 - 2
Front right wheel terminal 3 – 18 terminal 19 – 20
Rear left wheel terminal 2 – 10 terminal 5 - 6
Rear right wheel terminal 1 – 17 terminal 22 – 23
5. If the voltage is not with specification, the causes may be:

The clearance between sensor and teeth ring is too big.
Sensor malfunction.
The resistance of sensor is 1.0—1.3 k.
Distortion of teeth ring.

10、Removal and installation
(1)、 Spare parts offering
* HECU assembly dry type；
* HCU and ECU separate HCU wet type
(2)、Precaution on removing

Repair the faults after find the

cause for malfunction with test
instrument

Only open the package before

installation.

Only use original parts.
Only clean with soft cloth.
Don’t use compressed air or move the

vehicle when ABS is working.

Block the outlet for each pipe after

removing the parts.

Please use DOT 4 brake fluid.
Dip the seal and o-ring with brake liquid.
Check the function of ABS and conventional brake system is normal after

repairing.

Check if any leakage on each connector.

(3)、MK20-I HECU assembly Removal

Turn off ignition switch and disconnect (-) wire on battery.
Remove the harness from ABS assembly.

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