Chery A series. Manual — part 83

Fluid Refilling and Air Bleeding

* Wet type HCU

If the spare part is a wet type HCU, it is required to only refill the fluid and bleed the air in
accordance with the method available to the general brake system after replacing the HCU.

* Dry type HECU

If the spare part is a dry type HCU, apart from refilling the fluid and bleeding the air in
accordance with the method available to the general brake system, it is also required to
bleed the air of HECU’s second circuit after replacing the HCU.

* DTC display mode

System problem display code

Display code

No DTC

Never

occur

before

No

DTC

No problem current
(ABS warning lamp NOT
light)

Occur before

Random DTC

Never

occur

before

Non-random

DTC

Problem still exist
(ABS warning lamp lights)

Occur before

Random and non-random
DTCs

TROUBLESHOOTING QUICK INDEXING TABLE
DTC Failure Check Sheet Index

Diagnostic Code

Description of Failure

Diagnostic Details

65535

Electronic Control Unit (ECU)

Damaged

01276

ABS hydraulic pump

Motor fails to operate

00283

Front left wheel sensor

00285

Front right wheel sensor

00290

Rear left wheel sensor

00287

Rear right wheel sensor

Electrical and mechanical
failures

01044

ABS coding error

00668

Supply terminal 30

01130

Abnormal

ABS

operation

Unreasonable

signal

P-26

CAUTION WHEN FAILURE DIAGNOSING
The ABS adopts the electronic hydraulic control, so it is normal that the phenomena listed
in the table below occur under the normal operation of the ABS system, which shows they
aren't the failures.

Phenomena

Description

System self-check

sound

Sometimes, the sounds like the knock sound come from
the engine compartment after the engine starts, which is
the sound from the ABS self-check and doesn't indicate
it is abnormal.

Sound while the ABS

operates

1. Sound from the motor inside the ABS hydraulic unit.
2. Sound generated together with the brake pedal
vibration.
3. The suspension knocking sounds created due to
braking or the Creak sounds generated due to the
contact of tire with the ground when the ABS operates.

CAUTION: The tire may still give out the “Creak”

sound when the ABS operates normally.

ABS operates but long

brake distance

The braking distance of the vehicle with ABS is longer
than that of vehicle without ABS when the vehicle
travels on a snow or sand-gravel road, and thus a driver
shall be reminded to pay more attention to the road
condition when driving on the road above.

P-27

Repair Details of Random Failure:

In the electronic control system, the instantaneous and poor contact problem may occur in such
positions as the electrical circuit and input/output signal passage. Thus it causes the random failure
or generates the DTC when ECU self-checking. If the reason of failure still exists, the abnormal
parts can be found only in accordance with the DTC Failure Check Sheet, but sometimes the reason
to cause the failure will disappear automatically, so it is difficult to find out the reason of problem.

In this case, simulate the failure and check whether it reoccurs in accordance with the following
methods.

When the major reason may be vibration:

* Slightly swing the connection up and down;

* Slightly swing the harness up and down, left and right;

* Slightly swing the sensor up and down, left and right;

* Slightly swing the other motion parts such as wheel bearing.

Caution: If the harness is twisted off or pulled tightly and then broken, it is necessary to

replace it with a new one, especially it may cause the transient open/short circuit of
sensor due to the up and down movement of suspension system when the vehicle is
traveling. Thus the actual vehicle test must be conducted when checking the signals
from the sensor.

When the major reason may be over hot or super-cold:

* Use a blower to heat the parts that you think it may be failed.

* Use the cold spraying agent to check the cold welding phenomenon.

When the major reason may be the over-high contact resistance in the power supply circuit.

* Turn on all electrical switches, including the headlamp and rear defroster switches.

If the failure doesn’t reoccur here, it may be diagnosed and repaired only when the failure occurs at
next time. The random failure will generally become worse only, and is difficult to get better.

P-28

DTC Failure Check Sheet Index

Condition of Failure
Turn the ignition switch to “ON” (under the engine shut down), and the ABS
warning lamp doesn’t light
The warning lamp doesn't extinguish after the engine starts

Uneven braking force at both sides
Braking force shortage
ABS fails to operate when slightly stepping on the brake
pedal (the vehicle is in stationary state)

ABS operates when slightly stepping on the brake pedal
(the vehicle is in driving state)

Abnormal ABS

operation

The brake pedal vibrates seriously when the ABS works

Too long brake pedal travel
Great force required to step on the brake pedal

Without DTC output (fail to communicate with the diagnostic tester)

DTC FAILURE CHECK SHEET

ABS hydraulic pump

Possible Cause

1. The DTC is 01276

[Description] The ABS ECU will monitor the motor failure to

operate normally, and then record this DTC when the

vehicle speed exceeds 20 km/h.

[Hint] The occurrence of this DTC may be caused due to the

disconnection of harness between the motor and ECU.

Use the hydraulic unit function of the diagnostic tester

to test or drive the motor and take this testing.

* Power supply broken

circuit or earth

* Motor harness

uncoupling

* Motor damaged

Caution: If the battery discharges excessively, the motor will fails to be driven, and thus we

shall confirm firstly whether the battery voltage is normal before the motor drive
testing is conducted, and the vehicle shall be in stationary state when the motor drive
testing is conducting.

P-29