Slide đào tạo hệ thống phanh ABS trên xe khách

Components Description ABS Control Module Connector 7 Main power supply 8 Main power supply 9 Main power supply 2.FRT/LH Pressure modulator valve inlet 3.FRT/LH Pressure modulator ground

ANTI-LOCK BRAKE SYSTEM

(Heavy Duty Truck)

Learning Goals (You Can…)

 Understand Characteristics of the Anti-Lock Brake System

 State Control Logic

 Understand how ABS Components are controlled, operated and checked

 State input and output element of the system

 Read trouble codes with/without Hi-Scan Pro

 Troubleshoot

 Repair ABS

 Understand System Layout and Location

Characteristics

 Stability

 Steerability

Exercise

What is the characteristics of the ABS?

Discuss your opinion in the group and make a note of the most important items

ABS General

Maximum Brake Force Utilization

Brake force coefficient µB as function of brake slip 

Exercise

ABS Control Cycle

ABS General

Self Diagnosis Initiate Line

ECU

Pressure Module Valve

Warning Lamp

Valve Relay Self Diagnosis

ASR Information Indicating

Exercise : Diagram of Input / Output

Please fill out input and output element on the block diagram

ASR Valve

ABS General

System Layout

Air Over Hydraulic Brake- 6×4 Dump Truck

Full Air Brake - 6×4 Tractor

System Layout

Location

Pressure Control Valve for Front (A.O.H)

System Layout

Location

Pressure Control Valve for Rear brake

System Layout

Location

Wheel speed sensor - Front Wheel speed sensor - Rear

System Layout

Components Description

ABS Control Module

The ECM is the brain of the ABS system

It receives information from the sensors and sends signals to the ABS valves

ECM is installed at the underneath the seat of the passenger side

Components Description

ABS Control Module Connector

7 Main power supply

8 Main power supply

9 Main power supply

2.FRT/LH Pressure modulator valve inlet 3.FRT/LH Pressure modulator ground 4.FRT/LH Wheel speed sensor 5.FRT/LH Wheel speed sensor

4.FRT/RH Wheel speed sensor 5.FRT/RH Wheel speed sensor 7.FRT/RH Pressure modulator valve outlet

8.FRT/RH Pressure modulator valve inlet

9.FRT/RH Pressure modulator valve ground

1.RR/LH Pressure modulator valve outlet

2.RR/LH Pressure modulator valve inlet

3.RR/LH Pressure modulator valve ground

4.ASR Ground 5.RR/LH Wheel speed sensor 6.RR/LH Wheel speed sensor 7.ASR Power supply

8.RR/RH Wheel speed sensor 9.RR/RH Wheel speed sensor 10.RR/RH Pressure modulator valve outlet

11.RR/RH Pressure modulator valve inlet

12.RR/RH Pressure modulator valve ground

Exercise : ABS Control Module : Service Advices

• Do not expose ABS ECU to splash-water, mud, dust or

mechanical stress such as drop down etc.

• Do not expose ABS ECU to splash-water, mud, dust or mechanical stress such as drop down etc.

• Do not touch the electrical connectors with fingers or

parts other than the wiring harness plugs

• Do not touch the electrical connectors with fingers or

parts other than the wiring harness plugs

• Never weld on a vehicle while ECUs are connected

• Never start the Engine other than the own battery as long

as ECUs are connected

• Never start the Engine other than the own battery as long

as ECUs are connected

• Never run the Engine without a securely connected battery

• Never open an ECU nor try to repair it

If you have vehicles with ABS ECU, how you handle it?

Discuss your service points in the group and make a note of the most important items

Components Description

Wheel Speed Sensor

Minimum output voltage : 0.75 V

Components Description

Components Description

connect securely and tight

use grease before assembly avoid strong wire bends

Fix the wires securely in order to prevent chafe marks or other damages

use grease before assembly

do not use force by tools for installing the sensor

Exercise : WSS: service advice

When servicing wheel speed sensor , Discuss your service points in the group and make a note at the point as the shown in the figure

Components Description

Wheel Speed Sensor - Output Signal (Normal)

Components Description

Wheel Speed Sensor - Output Signal (Abnormal)

Components Description

Wheel Speed Sensor - Output Signal (abnormal)

0.9 ~ 2K Ohm

> 30k Ohm

to chassis ground

> 30k Ohm

to chassis ground

Pin 1 (Green/Yellow)Pin 2 (Blue)

Pin 3 (Brown)

Resistance Check Specification : 11 ~ 16.5 Ω

Pin 1 & 2, Pin 1 & 3

Inlet Port (supply)

Pressure Increase Mode

Operational Principle

Operational Principle

Pressure Hold Mode

Operational Principle

Pressure Dump Mode

ASR switch ?

Function

Operational Condition

When one side wheel is caught at slippery road or

muddy surface, the slipping wheel idles, that the

vehicle is hard to run power train (differential, axle

shaft) In order to compensate idling for stability,

the ASR, feature controls to brake the idling wheel

properly and transfer the rotating force to the other

wheel to enable launching

•Vehicle Speed : 40 km/h or less

•Speed Difference between RH and LH Wheels : 25km/h or

more

•Brake Pedal should not be depressed

Please Describe what is ASR and its function

To make sure the ABS lamp is operating, drivers should check the lamp

every time the vehicle is started

The ABS ECM continuously checks the state of the electrical integrity of

ABS and if detects a failure, it inform the fault codes through the SRI

lamp flash

Troubleshooting

System diagnosis step indicator check

Turn on the IG switch Connect Pin 13 and 12 for 1 second Read trouble code

Troubleshooting

Active fault

Blink code 2-3 : Fault in ABS modulator valve, right rear drive axle

1st digit(1-8 flashes) 1.5 sec.Pause 2nd digit(1-6 flashes)

Repeat

Continues until ignition is turned off

Stored faults

Troubleshooting

Blink code 5-2 : Sensor signal erratic, left front steer axle

3-4 : Excessive air gap, left rear drive axle

Connect Pin 13 and 12 for 0.5~3 second

System OK

Troubleshooting

Blink code 1-1 : System OK

Clearing faults

Troubleshooting

System configuration code

1 : 6S/6M(6X2 with ASR), 2 : 4S/4M, 3 : 4S/3M system

4 : 6S/4M, 5 :

8 Quick blinks - faults cleared Pause 4 sec. System ID (3)

System ID (3)

Continuous until ignition is turned off

37 13 12

Connect Pin 13 and 12 for 3~6.3 seconds

System ID (3) Pause 4 sec.

37 13 12

Connect Pin 13 and 12 for 3~6.3 second

Troubleshooting

Blink Code Identification

2 ABS modulator valve 1 Right front

3 Too much sensor air gap 2 Left front

4 Sensor short or open 3 Right rear

5 Sensor signal is abnormal 4 Left rear

6 Tooth wheel

4 ABS warning lamp

2 High power supply

3 Integral fault

5 Ground

Short to ground 4 - 2 4 - 1 4 - 4 4 - 3 ABS : 4

Incorrect pole wheel 6 - 2 6 - 1 6 - 4 6 - 3 Wheel 7

Wheel Speed Sensor

Troubleshooting

Blink Code Troubleshooting

L.F R.F L.R R.R Open circuit in/outlet 2 - 2 2 - 1 2 - 4 2 - 3 ABS : 13

Open circuit 2 - 2 2 - 1 2 - 4 2 - 3 Wheel 15

Shorted to ground 2 - 2 2 - 1 2 - 4 2 - 3 disabled 16

Troubleshooting

Blink Code Troubleshooting

Diagnosis 1 voltage ABS : right front,

low voltage / open circuit right rear, disabled

Warning Lamp on Diagnosis 2 voltage ABS : right front,

low voltage / open circuit right rear, disabled

Over voltage diag 1 or 2 8 - 2 All valves disabled 49

Troubleshooting

Repair Instruction

rotor run out, reinstall sensor to rotor.

Troubleshooting

Repair Instruction

12 Check sensor wiring and connectors for intermittent contact

13 Check modulator valve wiring

14 Check modulator valve wiring

15 Check modulator valve wiring

16 Check modulator valve wiring

17 Check wire Output is shorted to battery supply

19 Check wire Output is shorted to ground

21 Check ground for battery output, wiring, valve

26 Check supply wire an fuse Supply voltage is too low

40 Check wire and and bulb Was blink code switch activated

longer than 16s ? Output detects no load to plus.

54 Replace ABS electronic if fault detection repeats

55 No modulators connectoed Fault not memorized

56 Check airgaps respectively vehicle use One axle was much

faster than other

57 The modulator was activated longer than 3 minutes After a

delay time fucction is normal

58 Replace ABS electronic if fault detection repeats

59

Check wire DBR-output is not connectoed to a load Load was onece detected If load is not permanently supervisable check parameter setting

Well working components removed due to wrong diagnosis.

Exercise : Top 5 Field Problems

Discuss your experience regarding ABS problem in the group and make a note of the most important Top 5 field problems

Troubleshooting

PCV-A1 (LH) Rear Wheel

2 4 3 1 050-4P DTC

CHASSIS WR`G

2 3 1 8 9 10 6 090-10P

PCV-A1 (RH) S/VLV Front Wheel

ABS ECU

18 3 16 4 15 13 2 9 10 8

AMP-18P 1

30 2.OBW

31 2.OG

6 2 1 3

L2 L1 A2 A1

Schematic Diagram

Fuse 27 5A

Fuse &

relay box

Exhaust brake system

Exhaust brake system

DBR Relay

ON input

Ground Diagnosis

A17-2

A17-2 MA04 11

5 4

3 G10 Diagnosis connector 1

ABS controlmodule

Fuse 15 5A

Fuse details To diagnosisconnector

MA04 A17-2

2 11

Memory power

Wheel speed inputs

ABS IND.

A17-1 CA02 C56 13

7

8 9

2 3

14 15

5 2

7 6

4 1

8 3

1 2

1 2

1 2

1 2

Front left WSS

Front right WSS

Rear left WSS

Rear right WSS

ABS controlmodule

Case Study

Diagnosis by means of scanner (Hi-Scan)  No trouble code

Sensor resistance is normal : 1100~1200 Ω

Sensor power supply is normal : 3.8 ~ 4.1 V

Test drive with connecting scanner and check sensor resistance during driving

Case Study

Case 2.

Symptom

Rear wheel is locked when brake pedal is pressed

Vehicle : Heavy Duty Truck Engine : D6A Model Year : 2003 Mileage : 60000Checked Item

Brake lining clearance : Normal

Automatic slack adjuster : Normal

Brake chamber : Normal

Replaced ABS ECU : Same problem occurred

Self diagnosis by scan tool : No trouble code

Cause of Problem

Rear RH and LH Wheel speed sensor connector is interchanged

Remedy

Connect correctly