Brake sistem Nissan

BRAKE SYSTEM DIAGNOSIS

1

STEP 2 CHA BRTN0202AJ

Diagnose & Repair Electronic Brake Systems

PERFORMANCE: • Be able to describe the basic electronic controlled brake system

outline for ABS, EBD, TCS and VDC. • Be able to describe the function of the electronic controlled brake

system. • Be able to diagnose the trouble diagnosis of the electronic controlled

brake system.

RESOURCES: The following resources have been prepared for this module.

• NISSAN vehicle • Digital multi-meter • CONSULT-ll • ESM

OBJECTIVE

CHA0038


2


• Perform inspection for the electronic brake system of a NISSAN vehicle within 30 minutes.

SKILL CHECK


3


CONTENTS

1. ELECTRONIC BRAKE CONTROL SYSTEM

OUTLINE

2. ABS (ANTI-LOCK BRAKE SYSTEM) 1) ABS Outline 2) ABS Operation

Here’s what you do . . . . (1)

3. EBD (ELECTRONIC BRAKE-FORCE DISTRIBUTION) 1) EBD Outline 2) EBD Operation


4. TCS (TRACTION CONTROL SYSTEM) 1) TCS Outline 2) TCS Operation


5. VDC (VEHICLE DYNAMICS CONTROL) 1) VDC Outline 2) VDC Operation


6. SYSTEM COMPONENTS 1) System Layout 2) Wheel Rotation Sensor (Sensor and

Sensor Rotor) 3) Control Module 4) Yaw Rate/Side G-Sensor (Vehicle with

VDC) 5) G-sensor (Vehicle with 4WD) 6) Steering Angle Sensor (Vehicle with VDC) 7) VDC OFF Indicator Lamp (For vehicle with

VDC) 8) SLIP Indicator Lamp (For vehicle with VDC

and TCS) 9) ABS Warning Lamp

7. HYDRAULIC CIRCUIT

1) Component Parts and Functions of Oil Pressure Devices

TARGET

Ability to go to an ESM topic destination

Ability to read an ESM

Ability to describe the operation of the electronic brake control system

Ability to describe the operation of ABS

Ability to describe the operation of EBD

Ability to describe the operation of TCS

Ability to describe the operation of VDC

Ability to perform the trouble diagnosis of the electronic brake control system


4


CONTENTS 8. TROUBLE DIAGNOSIS WORK FLOW

1) Locate Malfunction Area 2) Confirm Precautions and For Correct and

Quick Diagnosis 3) Perform Preliminary Check 4) Confirmation of Warning Lamp and

Indicator Lamp 5) Confirmation of CONSULT-ll Display 6) When ABS is Not Displayed on the

CONSULT-ll Screen 7) Perform Self-Diagnosis 8) Check or Repair Malfunctioning Part 9) Erase the Self-Diagnosis Result 10) Perform Diagnostic Procedure for

Symptom 11) Confirm Symptom 12) Perform Self-Diagnosis Again

Here’s what you do . . . . (5) SKILL CHECK

TARGET

If you feel confident about your knowledge and skills of these tasks, you can proceed to the next module. Ask your course instructor for guidance.


5


1. ELECTRONIC BRAKE CONTROL SYSTEM OUTLINE

The electronic brake control system improves the driving stability by satisfying the braking performance, starting performance and turning performance at the same time. These performances can be obtained by each function of ABS, TCS, EBD and VDC. These systems are related to each other as shown in the figure below. You will study these systems to understand what kind of control is performed by each system.

2. ABS (ANTI-LOCK BRAKE SYSTEM)

1) ABS Outline The vehicle becomes unstable if the wheels lock when braking on a slippery road. Moreover, the braking distance will become longer. The ABS controls the braking force (wheel cylinder fluid pressure) electronically detecting wheel rotation while braking and avoids the locking of each wheel. Thus, the vehicle stability while fully braking and the turning performance while braking are increased. The ABS system consists of electronic and hydraulic units and components.

FUNCTION AND EFFECT OF ABS 1) To ensure the proper steering operation while braking 2) To be able to turn away from obstacles because the steering is secured 3) To ensure the vehicle stability by preventing flat spins

Watch a video to obtain technical information regarding the ABS function and effect.

Watch a video

CHA0039

TCS

ABS

EBD

VDC


6


CHA0040

Brake pressure

Slip

Vehicle speed

Vehicle stops

Speed of wheels

Bra

ke p

ress

ure

Spe

edWheels are locked

Time

2) ABS Operation

ABS is designed to control brake fluid pressure so that the wheels are prevented from locking during abrupt braking. More specifically, adequate control of brake fluid pressure maintains the optimum “slip” ratio between the wheels and road surface, thus stopping the vehicle firmly and quickly.

When full braking is applied, the wheel speed becomes lower than the vehicle speed resulting in slippage between the tires and road surface. The amount of slippage is shown as the red shaded area in the figure on the right. The ABS controls the brake fluid pressure to minimize the slippage in order to prevent the vehicle from losing driving control due to wheel locking. This slippage is called the slip ratio. Slip ratio= (Vehicle speed – Wheel speed) /Vehicle speed The slip ratio is controlled by the ABS to maintain the optimum condition (0.15 - 0.30).

The maximum braking performance can be obtained when the slip ratio is controlled to be around these figures.

The operation of the ABS is explained in the e-Learning program provided here.

e-Learning


What are the three functions and effects of the ABS? 1) 2) 3)

Self-check


7


CHA0041

Front brake force Rear brake force

Front brake force Rear brake force(same as 1.)

Front brake force Rear brake force(larger than 1.)

EBD effectiveness (same braking force)

1. Light load

2. Heavy load(without EBD)

3. Heavy load(with EBD)

CHA0042

Ideal braking force distribution: loaded

EDB braking force

Current type (P-value)

Ideal braking force distribution: unloaded

Bra

king

forc

e of

rear

whe

el

3. EBD (ELECTRONIC BRAKE-FORCE DISTRIBUTION)

1) EBD Outline

EBD is adopted into the ABS system in order to keep the brake performance stable (regardless of the loading condition of the vehicle). Its function is to control the braking force distribution to the front and rear electrically according to the loading condition. When the load distribution on rear wheel side increases, it divides brake force ideally according to the skid ratio difference of the tires between the front and rear. A load sensing valve (LSV) and a proportioning valve (P-valve) control the fluid pressure of the rear brake mechanically. Instead of these systems, EBD logic is built into the ABS system, and it operates the brake force ideally.

The load sensing valve (LSV) mechanically controls the rear brake force depending on the weight of the load. EBD works the same as LSV operation, but it does not sense the load on the vehicle. EBD monitors the front and rear wheel skid ratio by using ABS components. The EBD does not have any components, but its logic is built into the ABS system. The rear brake force is controlled on demand electrically and ideally. As a result, the system provides better brake effect for any vehicle weight.


8


CHA0043

ABS valve operation

Inlet valve

Outlet valveOFF

OFF

OFF

OFFOFF OFF

ON ON

EBD control threshold

Rear wheel speed

Front wheel speed

Vehicle speed

ABS control threshold

Spe

ed

Time

Front wheel fluid pressure

Rear wheel fluid pressure

EBD controlABS control

Flu

id p

ress

ure

Time

2) EBD Operation The EBD monitors the difference of front wheel skid and rear wheel skid. When the difference becomes greater than a certain specification, EBD holds the rear brake fluid pressure to increase in order to make the front and rear wheel skid become equal. And after the difference is returned to the specification, EBD allows for increasing the rear brake fluid pressure again. The figure on the right shows how EBD works and ABS valve operates. When the difference of the front wheel skid and rear wheel's one exceeds EBD control threshold, the inlet valve of ABS will close and hold the brake pressure that applies. After the difference is returned into the EBD control threshold, the inlet valve of ABS opens and allows the fluid pressure to apply to the rear wheel cylinder.

The operation of the EBD is explained in the e-Learning program provided here.

e-Learning


Describe the function of the EBD briefly.

Self-check


9


CHA0044

(2) Rear wheel speed

(1) Front wheel speed

(4) Secondary throttle opening

(3) Throttle openinig

(5) Rear brake pressureTCS OFFTCS ON

TCS OFFTCS ON

TCS OFFTCS ON

Wheel speed

Throttleopeningangle

Rear brakepressure

0

0

100%

Time

Time

Time

0%

TCS ON thresholdTCS OFFthreshold

4. TCS (TRACTION CONTROL SYSTEM)

1) TCS Outline On a road surface that is easy to cause slippage, a decrease in driving stability due to tail spin or unsatisfactory acceleration due to driving wheel spin occurs when starting or during sudden acceleration. The TCS controls the engine torque and brake force of the driving wheels using the various devices that are electronically controlled. As a result, the TCS prevents the driving wheels from spinning to increase the starting and acceleration performance and the driving stability and safety. 2) TCS Operation 1. Taking the average speed of the front

wheels as a base (1), the wheel speed of the rear (driving) wheels (2) is continuously monitored and compared.

2. The driver opens the throttle (3) and the speed of the rear wheels increases as a result. When the wheel speed exceeds the preset TCS ON threshold, the TCS turns itself ON. The secondary throttle (4) closes as the rear brake oil pressure is increased (5).

3. When the rear wheel speed decreases to a level between the thresholds of TCS ON and TCS OFF, the throttle position and the brake oil pressure level are maintained.

4. Finally, when the rear wheel speed drops below the TCS OFF threshold, the system switches itself OFF, opening the throttle and decreasing the brake oil pressure.

5. Until all tendencies have completely disappeared, steps 2 through 4 are repeated. The TCS function is explained in the e-Learning program provided here.

e-Learning


Describe the function of the TCS briefly.

Self-check


10


5. VDC (VEHICLE DYNAMICS CONTROL)

1) VDC Outline The VDC automatically improves the driving stability by controlling the braking force of the four wheels respectively and the engine output while avoiding obstacles. The system is operated by the controlling function according to the deviation of the calculated side skid from the target while steering. 2) VDC Operation The control unit calculates the actual status of the vehicle during cornering based on the steering angle, yaw rate, deceleration, vehicle speed, etc. If the vehicle is in the oversteer/understeer status, VDC applies the brake force to the 4 wheels respectively to prevent these statuses. The VDC function is explained in the e-Learning program provided here.

e-Learning

CHA0045

Fuel cutsignal

Throttle control signal

CAN communication line

Electrical controlledthrottle

Front RH wheel sensor

Rear RH wheel sensor

: Electrical circuit: Fluid pressure circuit

Rear LH wheel sensor

Master cylinder

Pressure sensorActuator drive signal

VDC/TCS/ABC actuator

Yaw rate/side G-sensor

Front LH wheel sensor

Steeringanglesensor

A/T C/UECCS C/U Combination meter

VDC/TCS/ABS C/U


11


Oversteer:

The rear tires produce too much cornering force, and the vehicle has the tendency to go to the inside of the curve.

Understeer:

The front tires do not produce enough cornering force, and the vehicle has the tendency to go to the outside of the curve.

Slip angle:

The angle between the direction in which a tire is aimed or steered and the actual direction of tire travel.

Yaw :

The rotation force of the vehicle’s body around its center point as viewed from above.

CHA0046

Slip angle

Direction of wheel

Actual


12


CHA0058

Yaw rate signalLateral acceleration signalAcceleration/Deceleration signal

Steering angle signal

Calculating target slip angleCalculating actual slip angle

Controlling brake force Controlling engine torque

Comparing the actual and the targetCalculating the compensation level

CHA0047

Oversteer

Slip angle

time

time

time0

0

0

Front RH wheelbrake force

Engine torquereduction

Actual slip angle

Target slip angle

OUTLINE OF OPERATION FLOW VDC compares the actual slip angle of the vehicle and the target slip angle that is calculated by the control unit based on the steering angle signal and brake pressure signal that are controlled by the driver. Then, it controls the brake force and engine output torque to obtain the target slip angle.

The figure on the right shows the VDC operation. The situation is: A vehicle is in oversteer during a left turn while accelerating. When the actual slip angle deviates from the target value, the system applies the brake force and reduces the engine output torque.


13



Describe the function of the VDC briefly.

Self-check


14


CHA0048

13. Yaw rate/side G-sensor*

1. Front RH wheel sensor rotor

4. Front LH wheel sensor rotor

7. Rear RH wheel sensor rotor

10. Rear LH wheel sensor rotor

2. Front RH wheel sensor

5. Brake booster and master cylinder

8. Rear RH wheel sensor

11. Combination meter (Brake warning lamp, ABS warning lamp, VDC OFF indicator lamp, SLIP indicator lamp)

3. Front LH wheel sensor

6. ABS actuator and electric unit (control unit)

9. Rear LH wheel sensor

12. VDC OFF switch

16. Electric throttle control actuator

19. Transaxle assembly

14. Steering angle sensor

17. Engine

15. Throttle control signal

18. ECM

20. TCM

6. SYSTEM COMPONENTS

1) System Layout

Numbers in the illustration with display additional information when they are clicked. : Component parts in the shaded area in the figure above are common to ABS, EBD, TCS and

VDC. *The G-sensor is used for the ABS system of vehicles with 4WD.


15


CHA0056

Sensor

Knuckle

Front wheel sensor

Sensor housing(The sensorrotor is inte-grated into thebearing.)

2) Wheel Rotation Sensor (Sensor and Sensor Rotor) The sensor detects the rotational speed of each wheel and sends it to the control unit.

ACTIVE SENSOR (MAGNET ENCODER TYPE J31, V35, C11, K12, ETC.) • With IC in the detector and magnetized

sensor rotor, downsizing and weight reduction are promoted.

• Power is supplied to the detector circuit to read out magnetic flux. Magnetic force is detected electrically, and it is and converted to a current signal.

• As the sensor rotor rotates, the magnetic field changes. Changes in the magnetic field are converted to current signals (square wave signal). Signals are sent to the ABS control unit. Changes in the magnetic field are proportional to the wheel rotation speed.

The circuit in the wheel rotation sensor of an active sensor type may be damaged if a multi-tester is used to measure the resistance. Use CONSULT-ll for examination to check whether the sensor is OK or NG.

CHA0057

Line of magnetic force

Magnetic rotorN

N

N

N

S

S

S

S

Sensor Amplification circuit

S N S N S N

Control unit

Sensor

Magnetic

Magneticencoder

flux

IC

SIG

V+

14mA

7mA


16


CHA0059

Sensor

Sensor rotor

Moving time of one tooth

Magnet

Magnetic flux

Tooth

V : Induced electromotive force

V

V

Control unit

Low carbon steet

Coil

CHA0060

ABS actuator and electric unit (control unit)

PASSIVE SENSOR (N16, A33, ETC.) The sensor unit consists of a gear-shaped sensor rotor and a sensor element. The element contains a bar magnet around which a coil is wound. The sensor is installed on the back side of the brake rotor. Sine wave current is generated by the sensor as the wheel rotates. The frequency and voltage increase(s) as the rotating speed increases.

Use the AC range to measure the sensor output.

3) Control Module The ABS actuator and control unit are integrated. The vehicle with VDC/TCS/ABS controls each function of VDC/TCS/ABS synthetically. The vehicle with the EBD function is equipped with the built-in EBD control function. The control unit receives a signal sent from each wheel speed sensor, computes wheel speed, etc. and sends a signal to the actuator which controls (decreases, increases and maintains) the brake fluid pressure in the wheel cylinders so that the wheels do not lock. 4) Yaw rate/side G-sensor (Vehicle with VDC) The sensor detects the yaw rate/lateral G/longitudinal G of the vehicle and sends the analog voltage signal to the ABS actuator control unit.

CHA0061

Yaw rate/sideG-sensor


17


5) G-sensor (Vehicle with 4WD) The G-sensor senses deceleration during braking to determine whether the vehicle is being driven on a high µ* road (asphalt road, etc.) or a low µ* road (snow-covered road, etc.). It then sends a signal to the ABS control unit. µ* (mju:): Symbol that stands for the friction coefficient. The reed switch turns on when it is affected by a magnetic field. During sudden deceleration (braking on a high µ road), the weight moves and the magnet in the weight moves away from the reed switch. The magnetic field then diminishes, and the reed switch turns OFF.

CHA0062

Braking (high road surface) Braking (low road surface)and Normal position.

Reed switch

G-sensor

Magnet Weight

Front

Under the driver's seat

Front

ONOFF


18


CHA0064

CHA0065

CHA0063

Steering angle sensorScrew

Spiral cableSteering anglesensor connector

BACK OF SPIRAL CABLE ASSEMBLY

6) Steering Angle Sensor (Vehicle with VDC) The sensor detects rotation, angular velocity and turning direction of the steering wheel and sends the signals to ABS actuator control unit through CAN communication. 7) VDC OFF Indicator Lamp (For vehicle with VDC) The lamp turns ON when a malfunction occurs in the electric system of EBD and VDC/TCS/ABS. It also turns ON when the VDC/TCS function is arbitrarily canceled. When the ignition switch is turned ON for the lamp check, the lamp turns ON for about one second and then turns OFF.

8) SLIP Indicator Lamp (For vehicle with VDC and TCS） The lamp turns ON when a malfunction occurs in electric system of EBD and VDC/TCS/ABS. It turns ON when the VDC or TCS function operates. When the ignition switch is turned ON for the lamp check, the lamp turns ON for about one second and then turns OFF.


19


CHA0066

CHA0067

ABS actuator and electric unit (control unit)

Master cylinder

Primary side Secondary side

Pump

Outlet valve

Outlet solenoid valve




Returncheck valve

Returncheck valve

Returncheck valve

Returncheck valve

Inlet solenoid valve Inlet

solenoid valve

Inlet solenoid valve

Inlet valve

Inlet valve

Motor

Reservoir Reservoir

Front RHcaliper

Rear LHcaliper

Front LHcaliper

Rear RHcaliper

Inlet solenoid valve

9) ABS Warning Lamp When a malfunction occurs in the electrical system, the lamp turns ON and warns that the brake system is in the fail-safe mode and the conventional brake system is in operation. The system is functioning normally if the lamp turns ON and then turns OFF after one second when the ignition switch is turned ON. The ABS warning lamp and the brake warning lamp turn ON at the same time when a malfunction occurs in the EBD system.

7. HYDRAULIC CIRCUIT

HYDRAULIC CIRCUIT DIAGRAM


20


1) Component Parts and Functions of Oil Pressure Devices

Components Contents Solenoid valve (ABS control valve)

The solenoid valve increases, maintains or decreases hydraulic pressure in each wheel cylinder according to the signal from the ABS actuator control unit.

Reservoir The reservoir temporarily reserves the brake fluid pulled out from wheel cylinders to perform decompression of wheel cylinders effectively.

Pump The pump returns the brake fluid reserved in the reservoir by decompression to the master cylinder.

Motor The motor drives the pump according to the signal from the ABS actuator control unit.

Inlet valve (pressure increasing)

The inlet valve stops the sucked brake fluid from the reservoir to the pump from returning to the reservoir again.

Outlet valve (pressure decreasing)

The outlet valve stops the brake fluid discharged from the pump from returning to the pump again.

Return check valve The return check valve returns the brake fluid in the wheel cylinder to the master cylinder bypassing the orifice of the solenoid valve when the brake is released.

Damper room The damper room damps pulsation of the brake fluid and reduces vibration of the pedal when VDC/TCS/ABS is in operation.

Cut valve The cut valve blocks the fluid route from the master cylinder for the conventional brake system when VDC/TCS is in operation.

Suction valve The suction valve supplies the brake fluid from the master cylinder to the pump when VDC/TCS is in operation.

Obtaining technical information regarding the fluid circuit operation is explained in the e-Learning program provided here.

e-Learning


21


8. TROUBLE DIAGNOSIS WORK FLOW

Perform diagnosis referring to the flowchart described in the ESM in case a malfunction occurs in the electronic brake control systems.

CHA0068Inspection end.

Inspection start.Locate trouble area (using diagnostic worksheet).

Confirm “PRECAUTIONS” and “For Correct andQuick Diagnosis”.

Perform PRELIMINARY CHECK.

Do (Does) ABS warning lamp, brakewarning lamp, SLIP indicator lamp orVDC OFF indicator lamp light?

Erase self-diagnotic results, then drive the vehicle for more than one minute at 30 km/h (19 MPH) or more. Perform self-diagnostic.

Perform self-diagnostic again.

Check harness connector betweenABS actuator and electric unit (controlunit) and data link connector.

Perform diagnostic procedure forsymptom.

Confirm symptom.

Does “ABS” appear on CONSULT-II display?

Perform self-diagnostic.

Check or repair malfunctioning part.

Yes

Yes

OK OK

NGNG

NONO

1)

2)

3)

4)

9)

12)

6)

10)

11)

5)

7)

8)


22


CHA0069

Customer name MR/MS

Engine #

Incident Date

Symptoms

Engine conditions

Road conditions

Driving conditions

Applying brake conditions

Other conditions

Model & Year

Trans.

Manuf. Date

VDC/TCS does not work(Drive wheels slip whenaccelerating, etc.)

VIN

Mileage

In Service Date

Warning / Indicatoractivate

ABS does not work.(wheels slip whenbraking)

Firm pedal operationLarge stroke pedaloperation

Lack of sense of acceleration

When starting After starting

Low friction road ( Snow Gravel Other )

Bumps / potholes

Full-accelerationHigh speed corneringVehicle speed: Greater than 10 km/h (6 MPH)Vehicle speed: 10 km/h (6 MPH) or lessVehicle is stopped

Suddenly

Gradually

Operation of electrical equipment

Shift change

Other descriptions

Noise and vibration(from engine compartment)Noise and vibration(from axle)

TROUBLE DIAGNOSIS

ASKING COMPLAINTS

• Complaints vary depending on the person. It is important to clarify the customer's actual remarks. WHAT

KEY POINTS

Vehicle model

• Ask the customer about what symptoms are present and under what conditions. Use the information to reproduce the symptom while driving.• It is also important to use diagnosis sheet so as not to miss vital information.

[VDC/TCS/ABS]

......

WHEN Date, Frequencies......

WHERE Road conditions......

HOW Operating conditions,Weather conditions,Symptoms

......

1) Locate Malfunction Area Obtain detailed information from the customer to clarify the incident using the DIAGNOSIS SHEET described in the ESM.


23


2) Confirm Precautions and For Correct and Quick Diagnosis Check the items below before performing trouble diagnosis. Be careful that the customers do not misunderstand a normal operation to be an incident. 1. Motor operating sound During ABS operation, brake pedal lightly vibrates and

a mechanical noise may be heard. This is normal. 2. Sound of system operation

check Just after starting vehicle after ignition switch is turned ON, the brake pedal may vibrate or motor operating noise may be heard from the engine compartment. This is a normal status of the operation check.

3. Braking distance of ABS Stopping distance may be longer than that of vehicles without ABS when vehicle drives on rough, gravel, or snow-covered (fresh, deep snow) roads.

4. Improper tire size Improper brake pads

If the tire size and type are used in an improper combination, or brake pads are not Genuine NISSAN parts, the stopping distance or steering stability may deteriorate.

5. During sudden acceleration or abrupt steering

When the TCS or VDC is activated by sudden acceleration or a sudden turn, some noise may occur. The noise is a result of the normal operation of the TCS and VDC.

6. Driving on steep hill or bank When driving on roads that have extreme slopes (such as mountainous roads) or high banks (such as sharp curves on a freeway), the VDC may not operate normally, or the VDC OFF indicator lamp and the SLIP indicator lamp may turn ON. However, this is not a problem if normal operation can be resumed after restarting the engine.

It is important to obtain detailed information about the occurrence of the incident at the time of reception because it may be resolved by an explanation of the items above. 3) Perform Preliminary Check 1) Check the quantity of brake fluid, brake fluid leakage and brake pads. 2) Check loosening of electric terminal and battery. 3) Check ABS warning lamp, brake warning lamp, VDC OFF indicator and SLIP indicator.

Check the items above.

See the ESM for the actual description


24


CHA0070

Condition

Ignition switch OFF

EBD error

Soon after ignition switch isturned ON

When VDC/TCS is not func-tioning normally.

Soon after ignition switch isturned ON(System normal)

When the VDC OFF switchis turned ON. (VDC functionOFF)

VDC/TCS/ABSerror

ABS warninglamp

Brake warninglamp (Note 2)

VDC OFF indica-tor lamp

SLIP indica-tor lamp

(Note 1)

(Note 1)

Remarks

Goes out 2 secondsafter ignition switch is

turned ON.

There is an ABS actu-ator and electric unit

(control unit)error. (power groundor system malfunc-

tion)

Note 1 : Turns off after engine start.Note 2 : The brake warning lamp turns on during parking brake operation (when switch is on) and brake fluidlevel sensor operation (insufficient brake fluid).

: ON : OFF

4) Confirmation of Warning Lamp and Indicator Lamp Confirm the lighting status change of the warning lamp and indicator lamp according to the system malfunction.

5) Confirmation of CONSULT-Ⅱ Display Confirm that ABS is displayed on the CONSULT-ll screen. 6) When ABS is Not Displayed on the CONSULT-ll Screen Check the wiring of the ABS control module and CAN communication line, etc. when ABS is not displayed on the CONSULT-ll screen. 7) Perform Self-Diagnosis Perform self-diagnosis with CONSULT-ll. (Refer to the link for the method of diagnosis without CONSULT-ll.) 8) Check or Repair Malfunctioning Part Referring to ESM, check and repair the malfunctioning parts.


25


CHA0071

Symptom 4 : ABS does not workCAUTION:

ABS does not operate when the vehicle speed is 10 km/h (6 MPH) or lower.

Make sure that the warning lamp turns off approximately 2 seconds after the key switch is turned on or whendriving.

1. CHECK ABS WARNING LAMP DISPLAY

OK or NG

OK >> GO TO 3. Vehicle Speed Sensor Inspection in BRC -98 “Symptom 1 : Excessive ABS Function Operation Frequently”

NG >> Perform self-diagnosis. Refer to BRC-71. “SELF-DIAGNOSIS” (With CONSULT-ll). BBC-79. “On Board Self-Diagnosis” (Without CONSULT-ll).

9) Erase the Self-Diagnosis Result When the repair is completed, erase the self-diagnosis result and perform self-diagnosis again after running for more than 1 minute at a speed of 30 km/h or higher. 10) Perform Diagnostic Procedure for Symptom If the warning lamp is not turned ON, check and repair the detected malfunctioning system using the symptom matrix chart described in the ESM. 11) Confirm Symptom Confirm that the malfunction is not occurring again. 12) Perform Self-Diagnosis Again

Perform the final self-diagnosis and confirm that there is no malfunction.


26



There is a malfunctioning vehicle whose ABS warning lamp is ON and the ABS does not operate. Perform trouble diagnosis by referring to TROUBLE DIAGNOSIS WORK FLOW described in the ESM. 1) Which warning lamp is ON?

2) Write down the self-diagnosis result.

3) Check the malfunctioning part indicated by the self-diagnosis result. What kind of malfunction is it?

Self-check

At this point, if you feel confident about your knowledge and skills of these tasks, you can proceed to the next page for the skill check for this module.


27


Diagnose & Repair Electronic Brake Systems

• Use an actual NISSAN vehicle and perform the following skill check.

• Your course instructor will inform you about the location of the workstation and how you will perform this skill check.

• Complete the skill check within 30 minutes. Tell your course instructor when you are ready to start. Your course instructor will time you accordingly.

There is an incident in the brake control system on this vehicle. Diagnose and repair the incident and pinpont the location on the wiring diagram provided by your course instructor. The time limit is 30 minutes.

1. What is malfunctioning?

2. Write the items what you checked. For each item, diagnose and judge the result OK or NG.

What did you check? Result Judgement

1 OK / NG 2 OK / NG 3 OK / NG 4 OK / NG 5 OK / NG 6 OK / NG

3. What is the reason for your answer to the above question? Reason:

SKILL CHECK


28


COURSE INSTRUCTOR’S SIGNATURE

Signature:

Name:

Date: / /

Technician

Name:

Number:

Company:

Sign-off

Brake sistem Nissan

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