Chery A15. Manual — part 217

Chery A15 Maintenance Manual

Chapter Five: Anti-lock Brake System

Maintenance

I. Fault Diagnosis Flow Chart

Abnormal

Normal

Connect fault diagnoser with power off

Turn key switch to “ON” position

Turn on diagnoser power and select “

A15

” Series

Select “MK20-I/E ABS”

Select “Universal OBD-16 Diagnose Adapter”

Check communication

Refer to Uncoded Fault

Checklist for diagnosis

Fault code

Incidental fault

Constant fault

Record fault code

Clear fault code

Repair with reference to Incidental

Fault Repair Instruction

Repair with reference to

Fault/Fault Code Checklist

Clear fault code

Turn key switch to “OFF” position and disconnect fault diagnoser

Road test

Start

Chery A15 Maintenance Manual

End

II. Fault Diagnosis Precautions

ABS adopts hydraulic control, and the occurrence of following phenomena under

working condition of ABS is of normal but not fault.

Phenomenon Description

System self-checking noises

Impact-like noises sometimes may be heard in engine

compartment after starting engine, these are ABS

self-checking noises and considered normal.

ABS working noises

1. Noise made by ABS hydraulic control unit motor

2. Syntonic noise made by brake pedal

3. Suspension impact noise or rattle sound of tires

contacting road surface while ABS is working

Note: Tires may still make rattle sounds when ABS

is under working condition.

ABS works with long braking distance

The braking distance of vehicles with ABS sometimes

is longer than those without ABS on road covered by

snow or sandstone, so drivers must be extremely

careful when driving on aforesaid road surfaces.

III. Operation and Function Instruction of Fault Diagnoser

（

1） Connect diagnoser to diagnose socket with power off, and then turn on

ignition switch.

（

2） Turn on diagnoser power and select “A15 Series”.

（

3） Select “MK20-I/E ABS”.

（

4） Select the proper diagnose adapter.

（

5） Select applicable function items.

Chery A15 Maintenance Manual

IV. Incidental Fault Repair Instruction

Instantaneous poor contact may sometimes occur to electrical circuits and

input/output signals in electronic control systems and cause incidental faults or

display fault codes during self-checking of ECU. If the fault cause continues, check

against Coded Fault Checklist to identify the abnormal part. But sometimes, fault

causes will disappear by themselves, in which case it will be difficult to identify

problem causes.

Should the said case occur, imitate fault in following ways to check if the fault

reoccurs.

1. If vibration is the possible cause:

.

Slightly shake adapter vertically and horizontally.

.

Slightly shake wire harness vertically and horizontally.

.

Slightly shake sensor vertically and horizontally.

.

Slightly shake other moving parts such as wheel bearing.

Note: In case wire harness is broken due to overtwist or overtension, some

parts especially the sensor shall be replaced, for the vertical movement of

suspension system may cause temporary open/short circuit. Therefore, a

road test is necessary when checking sensor signal.

2. If overheat or overcool is the possible cause:

.

Heat the suspect part with a blower.

.

Check for cold welding with cool spray.

3. If too much power circuit contact resistance is the possible cause:

.

Turn on all electrical switches including head light and rear defrost switch.

If the fault does not occur again, the diagnosis and repair will not be carried out

until the reoccurance of the fault. Generally incidental faults will not get better

but worse along with the time.

Chery A15 Maintenance Manual

V. MK 20 Anti-lock Brake System

(1). Checking ABS Warning Light

Check if ABS warning light is turned on in the following order:

1. Turn ignition switch to “ON”, and ABS warning light is turned on for about 1.7

seconds and then goes out.

2. If the above does not happen, check fault code for faults.

3. If the warning light is not on at all, refer to Uncoded Fault Checklist.

(2). Reading Status Messages

Connect original diagnoser with the OBD-II diagnose socket at brake pedal, start the

diagnoser and read the status messages of ABS computer.

1. For examples, version number or part number of ABS and ECU.

A11-3550010

2. Coding: 01901

(3). Reading Fault Code

Enter “MK20-I/E ABS” and select “Fault Code”, then press “OK”, and the fault codes

will be displayed on the screen if any.

(4). Clearing Fault Code

1） Press “Clear” key after reading fault code.

2） The screen will display:

3） Press “Yes”, and the fault code will be completely cleared if the fault is

solved.

(5). Display Mode of Fault Code

Code Displayed for System Problem

Code Displayed

No code displayed

Never occurred before

No code displayed

No problems at present

(ABS warning light off)

Ever occurred before

Incidental fault code displayed

Never occurred before

Non-incidental fault code displayed

Problem continues

(ABS warning light on)

Ever occurred before

Incidental and non-incidental fault

codes displayed

Do you wish to clear fault code?
[Yes]: Clear (key on, engine off)