JAC S2 (Chassis). Instruction — part 12

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ABS control module unearthed

Check and restore

codes”

ABS control module fails

Check and replace

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Diagnostic flow chart of unlighted ABS warning light, no trouble codes

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Diagnostic flow chart of unlighted ABS warning light, no trouble codes (continue)

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Diagnostic flow chart of “unable to read ABS data stream”

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Diagnostic flow chart of “unable to read ABS data stream” (continue)

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Diagnostic flow chart of ABS warning light keeps lighting, no trouble codes

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Diagnostic flow chart of ABS warning light keeps lighting, no trouble codes (continue)

Diagnostic information and procedures

1. Self-diagnostics

ABS control module can implement self-diagnostics on system and check the faults within. Once it finds
any fault, it will set diagnostic trouble code (DTC), lighten the ABS warning light, and shut down the
ABS system.

2. Reveal DTC

Specific scan tool (diagnostic instrument) can reveal the DTC

3. Clear DTC

DTC which is in the memorizer of ABS control module can be cleared by scan tool (diagnostic instrument)

△Notice please verify whether the system works
normally after the clearance procedure, and whether the
DTC doesn’t appear again. The DTC cannot be cleared by
dismantling the connector of ABS control module,
disconnecting the battery or stopping the engine.

4. The following situations may cause intermittent failure or poor contacts:

1). Error in electrical wiring

2). Error in electrical connection

3). Stagnation in electric valve or electromagnetic valve

5. Initialization’s order

ABS control module will set out initialization test during every beginning of ignition period. The
initialization order is electromagnetic valve and pump motor. Once the failure is detected, ABS control
module will set corresponding diagnostics.

During initialization period, there will be some noises and vibrations, which are a part of normal system
operation. If the ABS control module finds no signal input in brake switch (when your feet are away from
the pedal), the initialization will be set out immediately. If there is signal input in brake switch (your feet
are on brake pedal), the initialization will not be set out till no signal input is detected, or the speed
reaches 25 Km/h.

(III) Diagnostic check on circuit

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1. System introduction

Circuit diagnostics can detect problems caused by failures of ABS or EBD. The diagnostic check on
circuit can lead the technicians to diagnose the failures.

2. Diagnostic procedures

The procedures of ABS/EBD’s maintenance come follow:

1). Check whether any mechanical failure exists in brake
system

(1). Is the liquid level of fluid reservoir correct?

(2). Is there any pollution in the brake fluid?

(3). Is there any leakage in brake’s master cylinder or ABS hydraulic assembly?

(4). Do all spare parts in brake system work normally?

(5). Is there any stagnation during braking?

(6). Is the braking steady?

(7). Are the brake shoes broken?

(8).Are the bearings broken?

(9). Do all sensors and harness work normally?

(10). Check whether the sensors’ connectors and tooth rings are broken, and check the wheel’s abrasion
degree

(11). Test the vehicle on road, check and correct the situation.

2). Set out diagnostic check on circuit

Please follow the corresponding diagnostic procedures during the circuit check. When all systematic
failures are eliminated, please clear the trouble code of ABS. Please refer to the following chart for
specific procedures and solutions.

Chart of diagnostic check on circuit

Procedures Concrete measures

Next measure

Y

N

1

If possible, connect and install all spare parts which have been
disconnected or dismantled

Turn to
procedure 2

Turn to
procedure 4

Turn the ignition switch to "ON", and the engine is dead

When install the appropriate diagnostic instrument on DLC,
does it communicate with ABS control module?

2

Are there any current or past DTC stored?

Turn to
procedure 3

Turn to
procedure7

3

Record the current or the past DTC, and the historical data, like
the times when each DTC appears, the time when each DTC
first appears, the latest time when each DTC appears, the DTC's
setting speed, and other relevant data that can help the
diagnostics. Do not clear DTC before the diagnostic instrument
record the information

Turn to
procedure 5

Turn to
procedure 6

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4

Can the instrument communicate with other modules that in the
same data circuit?

5

Refer to "no communication with ABS control module" in
failure procedure of ABS control module

6

Refer to "data chain connector unit of electrical terminal"

7

Shut down the engine

Turn to
procedure 8

Turn to
procedure 9

Wait for 10 seconds

Start the engine

Observe the ABS warning light after the engine has started

8

Does there any light keep lighting?

Turn to
procedure 9

Turn to
procedure
10

9

Refer to failure procedure of the corresponding light “keeps
working”

10

Refer to failure procedure of the corresponding light “out of
operation”

IV Air-removal of ABS system

(I) Special tool

No.

Tool

Mechanical dimension

Introduction

1

Fault diagnostic
instrument

Systematic trouble diagnostics for
ABS/ESP

(II) Conditions that needs air-removal

Should any of the following condition happen, it is necessary to remove air from ABS:

1. The traditional air-removal method for brake pipeline cannot achieve the pedal’s height that needs.
2. The ABS controller assembly is replaced.
3. Extreme fluid loss
4. Suspicion that some air exists in ABS controller.

This program, by using diagnostic instrument, can drive the system’s valve, run the pump motor, and
remove air from secondary circuits. These circuits are closed during normal condition, and open during
only the initialization or ABS’s working periods. The automatic air-removal program can open these
secondary circuits, exhaust all air and collect it inside the ABS controller assembly, where it can be
exhausted out of the system.

(III) Air-removal of ABS

1. Necessary tools

1). Diagnostic instrument installed with correct software

2). Brake fluid

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3). Lifting jack

4). Gas-exhaustion bottle with hose that can recycle fluid in the vehicle

5). Appropriate safety equipment, like safety glasses

6). Two maintenance personnel: one needs to stamp the brake pedal and control the instrument, and
the other one needs to maintain the liquid level of hydraulic oil in master cylinder, and adjust the air-
removal screw according to the instrument’s judgement.

2. Preliminary check

1). Check the battery’s charging condition, and repair the battery and charging system if necessary

2). Connect the diagnostic instrument and choose the current or past DTC. Clear all DTC before the
procedure of ABS’s air-removal. If DTC cannot be cleared, please eliminate the failures first.

3). Check whether any damage or leakage exists on vehicle’s appearance, and repair them if
necessary.
△Notice by pressing the “EXIT” button on diagnostic instrument, you can terminate auto air-
removal program at any time

3. Air-removal in the car

1). Choose “auto air-removal program” and follow the instructions. (Please refer to practical program
in diagnostic instrument)

2). During basic and auto air-removal, please stamp the brake pedal to maintain the liquid level of
brake fluid in master cylinder

3). When exhaust air for a wheel, keep the hose jointing with air-removal screw, and exhaust air into
chamber with brake fluid. The chamber must be 30mm higher than the bolt of hose filled with brake
fluid, in order to prevent air from entering brake pipeline.

4). The first step is basic air-removal. This step must be carried out before auto air-removal, in order
to get better pedal’s height and driver’s feeling, and maintain the ABS’s best performance.

5). The first step of auto air-removal is to loosen the pump and pressure-reduction valve for 30
seconds. Air-removal screw doesn’t need to be opened during this step. The brake pedal keeps
increasing and reducing pressure during the whole process.

6). During the next step, the instrument will ask the personnel to open one of the air-removal screws,
and the instrument will circularly check the pressure valve and pump motor for 30 seconds. The
brake pedal keeps increasing and reducing pressure during the whole process.

7). For the remaining air-removal screws, the instrument will repeat step 6 to remove air.

8). When the auto air-removal program completes, the instrument will display relevant information.

9). Stamp the brake pedal to test the pedal’s height and driver’s feeling. Repeat step 1 to 8 till the
pedal’s feeling is acceptable.
△Notice when repeat the operation, the auto air-removal program may stop temporaily into
“cooldown” mode
△Notice only continue the next step when the time for the current step is up, and all steps cannot be
skipped.

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4. Auto air-removal

1). Launch the failure diagnostic system for JAC Motors

2). Choose the V10.01 system for JAC Motors only

3). Launch the auto air-removal program

4). Carry out the first step

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5). Air-removal is in process

6). Step 1 is complete

7). Carry out step 2

8). Air-removal is in process

9). Step 2 is complete

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10). Air-removal is in process

11). Step 3 is complete

12). Carry out step 4

13). Air-removal is in process

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14). Step 4 is complete

15). Carry out step 5

16). Air-removal is in process

17). Air-removal process is complete

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V Front wheels’ ABS wheel speed sensor assembly

(I) Disassembly

1. Open the engine hood
2. Disconnect the negative cable of battery
3. Dismantle the front wheels, please refer to “wheels”
4. Dismantle front wheels’ cover, please refer to “front wheel’s cover”
5. Disassemble the front wheel’s ABS wheel speed
sensor assembly

1). Disconnect the harness connector of front wheels’
speed sensor

2). Uncouple the buckle that connects sensor’s harness
and vehicle body, two fixing points, and the fixing
point which connects with front shock absorber

3). Remove the fixing bolt that fixes the front wheel’s
speed sensor, and take out the sensor slowly.

(II) Installation

1. Install the front wheels’ ABS wheel speed sensor
assembly

1). Install the fixing bolt that fixes speed sensor

Tightening torque 8~10N.m
△Notice

1. Do not drag the sensor’s harness brutely

2. Mind the gap between speed sensor and signal’s
gear ring

Standard: 0.2~1.1mm

2). Install the buckle that connects sensor’s harness
and vehicle body, two fixing points, and the fixing
point which connects with front shock absorber

3). Connect the harness connector of front wheel’s

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speed sensor

2. Install the front wheels’ cover
3. Install the front wheels
4. Connect the negative cable of battery
5. Close the engine hood

VI Rear wheels’ ABS wheel speed sensor assembly

(I) Disassembly

1. Open the engine hood
2. Disconnect the negative cable of battery
3. Dismantle the rear wheels, please refer to “wheels”
4. Dismantle the rear seat’s cushion, please refer to “rear seats”
5. Dismantle the rear seat’s backrest, please refer to “rear seats”
6. Dismantle the rear seat’s rotating bracket
7. Dismantle C column’s trim and decorated board
8. Dismantle the rail-gate threshold’s cover
9. Dismantle the rear-gate threshold’s cover
10. Dismantle the tailgate’s side panel threshold’s cover
11. Disassemble the rear wheels’ ABS wheel speed
sensor assembly

1). Disconnect the rear wheels’ speed sensor’s harness
connector

2). Uncouple the buckle that connects sensor’s harness
and vehicle body, and the three fixing point which
connect with rear torsion beam

3). Remove the fixing bolt that connects the rear
wheel’s speed sensor and rear hub assembly, and take
out the sensor slowly.