ESP SSANGYONG NEW ACTYON SPORTS 2012 Workshop Manual

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5) EBD (Electronic Brake Force Distribution) System
System description ▶
As an add-on logic to the ABS base algorithm, EBD works in a range in which the intervention
thresholds for ABS control are not reached yet.
EBD ensures that the rear wheels are sensitively monitored for slip with respect to the front axle. If
slip is detected, the inlet valves for the rear wheels are switched to pressure hold to prevent a
further increase in pressure at the rear-wheel breaks, thus electronically reproducing
a pressure-reduction function at the rear-wheel brakes.
ABS features an enhanced algorithm which includes control of the brake force distribution
between the front and rear axles. This is called Electronic Brake Distribution. In an unloading car
condition the brake efficiency is comparable to the conventional system but for a fully loaded
vehicle the efficiency of the EBD system is higher due to the better use of rear axle braking
capability.
Advantages ▶
Elimination of conventional proportioning
valve EBD utilizes the existing rear axle
wheel speed sensor to monitor rear wheel
slip.
Based on many variables in algorithm a
pressure hold, increase and/or decrease
pulsetrain may be triggered at the rear
wheels insuring vehicle stability.
Vehicle approaches the ideal brake force
distribution (front to rear).
Constant brake force distribution during
vehicle lifetime.
EBD function is monitored via ABS safety
logic (conventional proportioning valves are
not monitorable). -
-
-
-
-
Ideal distribution
EBD start point
Cut-in point
Fixed distribution 1.
2.
3.
4.

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1. SPECIFICATION
1) Specification of Active Wheel Sensor
Description Specification Remark
Supplying voltage 4.5 ~ 16.0V
Output current (at 2.75 km/h of
vehicle speed)7mA(Lo) ~ 14mA(Hi)
Tightening torqueFront: 7.8 to 11.8 Nm
Rear: 7.8 to 11.8 Nm
Operating temperature-40 ~ 150℃
Operating frequency 1 ~ 2,500Hz
UnitDescription
Specification
ABS ESP
HECU Clock frequency: 32 MHz Clock frequency: 50 MHz
Memory: 128 KB Memory: 256 KB
Wheel speed
sensorActive type Active type Output: 7~14
mA
Steering wheel
angle sensorNone Max. detection angle speed:
1500 °/SecPulse duty:
50±10%
Operating voltage: 9 to 12 V
Sensor cluster None Yaw rate sensor + lateral G
sensor + longitudinal G sensor
(4WD)Mounting
direction should
be kept (CAN
communcation)
Longitudinal G
sensor4WD only None
Pressure
sensorNone HECU integrated

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2. SYSTEM LAYOUT
ESP System ▶
Sensor - front wheel speed
Sensor - rear wheel speed
Screw (7.8~11.8 Nm)
Clip - cable holder
Clip - sensor cable mounting rear
Plug - blind
HECU
Sensor - cluster
Nut (9.8~10.8 Nm)
ESP OFF switch
Steering wheel sensor 1.
2.
3.
4.
5.
6.
9.
10.
11.
12.
13.

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1. OVERVIEW
The ESP (Electronic Stability Program) has been developed to help a driver avoid danger of losing
control of the vehicle stability due to understeer or oversteer during cornering. The yaw rate
sensor, lateral sensor and longitudinal sensor in the sensor cluster and the steering wheel angle
sensor under the steering column detect the vehicle conditions when the inner or outer wheels are
spinning during oversteer, understeer or cornering. The ESP ECU controls against oversteer or
understeer during cornering by controlling the vehicle stability using input values from these
sensors and applying the braking force to the corresponding wheels independently. The system
also controls the engine power right before the wheel spin synchronized to decelerate the vehicle
automatically in order to maintain the vehicle stable during cornering.

11-8
ESP OFF switch
Located on the left side of
instrument panel.
Rear wheel speed sensor
Located on the both ends of
rear axle.Front wheel speed sensor
Located on the hub
assembly.Sensor cluster
Located at the bottom of
center fascia panel.
Steering wheel angle sensor
Located on column shaft with
contact coil.HECU assembly
Located near the brake
booster in engine
compartment and contains
the pressure sensor.
2. COMPONENTS

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3. PRECAUTIONS
The warning lamp flashes and warning beep sounds when the ESP is operating
When the ESP operates during vehicle movement, the ESP warning lamp on the instrument
panel flashes and beep comes on every 0.1 second. The ESP system is only a
supplementary device for comfortable driving. When the vehicle exceeds its physical limits, it
cannot be controlled.
Do not rely on the system. Keep on the safe driving.
Feeling when ESP is working
When the ESP system activates, the feeling can be different depending on vehicle driving
conditions.
For example, you will feel differently when the ESP system is activated during the ABS is
operating with the brakes applied and when the brakes are not applied on a curve.
If the ESP system operates when the brake is applied, the brake pressure will be increased on
the corresponding wheel which already has braking pressure for the ESP controls.
ARP Operation
During the ARP operation, vehicle safety (rollover prevention) takes the first priority and thus,
stronger engine control is in effect. Consequently, the vehicle speed decreases rapidly, so the
driver must take caution for the vehicle may drift away from the lane.
Noise and vibration that driver feels when ESP system is operating
The ESP system may transfer noise and vibration to the driver due to the pressure changes
caused by the motor and valve operations in a very short period of time. And, keep in mind
that the output and vehicle speed could be decreased without rpm increase due to the ASR
function that controls the engine power.

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4. WARNING LAMPS
1) ABS Warning Lamp
ABS warning lamp module indicates the self diagnosis and malfunction.
ABS warning lamp ON:
When turning the ignition switch to ON position, ABS warning lamp comes on for 3
seconds for self diagnosis and goes off if the system is OK (initialization mode).
When the system is defective, the warning lamp comes on.
When disengaging the connector, the warning lamp comes on.
ABS is not available during lamp ON. In this condition, Only normal brake system without
ABS function is available.
When the communication between warning lamp CAN module in meter cluster, the warning
lamp comes on. 1.
2.
3.
4.
5.ABS warning lamp
Brake warning lamp
ESP OFF indicator
ESP warning lamp/indicator
EBD warning lamp 1.
2.
3.
4.
5.

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2) EBD (Electronic Brake-force Distribution) Warning Lamp (Brake
Warning Lamp)
EBD warning lamp when the system perform the self diagnosis and when it detects the
malfunction of EBD system. However, the brake warning lamp comes on regardless of EBD
when the parking brake is applied.
EBD warning lamp ON:
When turning the ignition switch to ON position, ABS warning lamp and the brake warning
lamp comes on for 3 seconds for self diagnosis and goes off if the system is OK
(initialization mode).
When applying the parking brake, the brake warning lamp comes on.
When the brake fluid is not sufficient, the brake warning lamp comes on.
When disengaging the connector, the warning lamp comes on.
When the system is defective, ABS warning lamp and the brake warning lamp come on
simultaneously. 1.
2.
3.
4.
5.
When the solenoid valve is defective
When one or more wheel sensors are defective
When ABS HECU is defective
When the voltage is abnormal
When valve relay is defective a.
b.
c.
d.
e.
When the communication between warning lamp CAN module in meter cluster, the
warning lamp comes on. 6.
3) ESP OFF Indicator
ESP OFF indicator ON:
When turning the ignition switch to ON position, ESP warning lamp comes on for 3 seconds for
self diagnosis and goes off if the system is OK (initialization mode).
When the ESP OFF switch is pressed to turn off ESP function, ESP OFF indicator comes on. 1.
2.
4) ESP Warning Lamp
ESP warning lamp ON:
When turning the ignition switch to ON position, ESP warning lamp comes on for 3 seconds
for self diagnosis and goes off if the system is OK (initialization mode).
When the system is defective, the warning lamp comes on.
When the ESP function is activated, ESP warning lamp blinks with the interval of 2 Hz.
When the communication between warning lamp CAN module in meter cluster, the warning
lamp comes on. 1.
2.
3.
4.
5.
5) ESP OFF Switch
If ESP OFF switch is pressed, ESP function is deactivated and the ESP OFF indicator in the
instrument cluster comes on.
To resume the ESP function, press the switch again. At this time, ESP OFF indicator goes out.

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5. SYSTEM DESCRIPTION
1) Block Diagram of ESP HECU

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2) Operation of ESP System
The ESP (Electronic Stability Program) has been developed to help a driver avoid danger of losing
control of the vehicle stability due to understeer or oversteer during cornering. The yaw rate
sensor, lateral sensor and longitudinal sensor in the sensor cluster and the steering wheel angle
sensor under the steering column detect the vehicle conditions when the inner or outer wheels are
spinning during oversteer, understeer or cornering. The ESP ECU controls against oversteer or
understeer during cornering by controlling the vehicle stability using input values from these
sensors and applying the braking force to the corresponding wheels independently. The system
also controls the engine power right before the wheel spin synchronized with the ASR function to
decelerate the vehicle automatically in order to maintain the vehicle stable during cornering.
(1) Under steering
What is understeering? ▶
Understeer is a term for a condition in which the steering wheel is steered to a certain angle during
driving and the front tires slip toward the reverse direction of the desired direction. Generally,
vehicles are designed to have understeer. It is because that the vehicle can return back to inside of
cornering line when the steering wheel is steered toward the inside even when the front wheels are
slipped outward.
As the centrifugal force increases, the tires can easily lose the traction and the vehicle tends to slip
outward when the curve angle gets bigger and the speed increases.