Kia Optima: Electronic Parking Brake (EPB). Description and Operation
Description
The EPB is an electronic parking brake.
The EPB is different from existing parking systems which operated with the brake
pedal or the lever type. The EPB system sends the signal to the ECU when a driver
operates the EPB switch. The ECU operates the EPB actuator composed with motor gears.
EPB has several functions.
| - |
Emergency braking function by
hydraulic brake malfunction |
EPB Function
| 1. |
Static Switch Apply
| A. |
Manual apply of EPB switch
in stand still condition. |
| B. |
Clamping force control;
When parked on less than 8% slope, it is applied with Reduced Clamp
Force(RCF); Except for RCF condition, It is applied with full clamp
force More than 15 slope. |
|
| 2. |
Reduced Clamp Force on Flat (RCF)
| A. |
If EPB is applied on
less than 8% slope, it is applied with reduced clamp force. |
| B. |
When switch is pulled
for more than 3 sec, it is clamped to full clamp force. |
|
| 3. |
Static (Switch) Release
| A. |
Releasing EPB manually
by switch |
| B. |
To prevent danger situation,
it can be released only when ARC is fulfilled. |
Additional Release Condition (ARC)
| A. |
To prevent unintentional
release of EPB, there is condition to be met before releasing;
Example: IGN On + [Brake Pedal pressed]
|
Child Safe (Release Inhibit)
| A. |
With ignition switched
off, EPB cannot be released. |
|
| 4. |
Drive Away Assist (DAA)
| A. |
EPB is released automatically
when driver tries to move. |
| B. |
EPB is released when
accelerator pedal is depressed with gear shifter in moving position.
(D or R) ; Driver seatbelt should be buckled.
; Driver side Door + Hood + Trunk should be closed. |
|
| 5. |
Electric Controlled Deceleration
(ECD)
| A. |
When EPB switch is pulled
in dynamic condition, deceleration is realized by sending request
via CAN to the ESC. |
| B. |
ECD means deceleration
will be done via the ESC system, not by EPB Actuator;
Applied to the vehicle with ESC only.
|
|
| 6. |
Rear Wheel Unlocker (RWU)
| A. |
This function is for
vehicle with no ESC or failed ESC. When EPB switch is pulled in
dynamic condition, dynamic deceleration is generated by EPB actuator. |
| B. |
Clamp force will be controlled
to avoid locking of the rear wheels and ensure vehicle stability. |
|
| 7. |
Auto Apply
| A. |
With switching off ignition,
EPB will automatically apply the brakes. |
| B. |
Auto Apply is disabled
when Auto Hold switch is switch off. |
| C. |
The auto engage feature
does not activate if the power switch is turned off while the EPB
switch is pressed. |
|
| 8. |
Roll Away Reclamp (RAR)
| A. |
If vehicle rolls away,
EPB gets reapplied. ; Vehicle movement is monitored via wheel
speed.
; It can be active until CAN signal is available (5 min) |
|
| 9. |
High Temperature Reclamp (HTR)
| A. |
After detection of hot
brakes, EPB will reapply from closed brake state to compensate for
loss of clamp force during cooling of the brakes. |
| B. |
Activation condition:
over 350°C |
|
| 10. |
External Apply (EA)
| A. |
EA checks for an external
demand to apply the brake and reacts according to that demand;
With EA, Auto Hold → EPB takes over possible
|
|
| 11. |
Pad Change Mode
| A. |
Return the spindle nut
fully for pad replacement ; This mode can be entered via hand
tool connected to vehicle with OBD2 connector.
; Piston can be pushed in after entering Pad change mode |
|
| 12. |
Dynamic Standstill Detection
(DSD) This is how to operate the parking brake when there is no wheel
speed signal because of malfunction. Braking force can be applied while
the vehicle is in motion to slowly decelerate. If the EPB switch is continuously
pulled, then the parking brake can be engaged with maximum force.
|
| 13. |
P to X EPB is automatically
released when gear shift lever is moved from P position;
Engine on + Brake pedal condition is necessary. |
| 14. |
N to X EPB is automatically
released when gear shift lever is moved from Neutral position to moving
position. (D or R)
; It does not get released if the gear shift lever is moved to P or passes
through N rapidly.; Engine on + Brake pedal condition is necessary.
|
| 15. |
Roller Bench Mode (HU Function)
In Europe, parking force and force balance between left and right of EPB
is evaluated on roller bench.
This function detects roller bench test mode and develops special clamping
force increase pattern which is triggered by the apply switch input. |
| 16. |
Auto Adjust Function
| A. |
This function automatically
activates EPB apply and release cycle for every 1000Km driving and
helps to maintain same clearance regardless of brake pad wear status |
|
Parking Brake Emergency Release
| - |
The following procedure is for
releasing the parking brake when EPB failure occurs. |
| - |
This is the last resort for releasing
the EPB when the parking brake cannot be released electrically or by using
a diagnosis scanner because of motor or EPB damage, or power line disconnection. |
| - |
The task must be performed on
a flat surface and with safe surroundings. When you release the parking
brake, be sure to keep the vehicle stationary. (Perform this task only
after you make sure that preventive measures are taken in case the vehicle
moves when the parking brake is released.)
|
| 1. |
Use a standard hexagonal wrench
to remove the screw (A) on the back of the rear caliper (2 of them) |
| 2. |
Using the same hexagonal wrench,
turn the hexagon part on the floor inside the spindle (B) clockwise by 0.5
- 1 complete turn. |
| 3. |
The parking brake is released. |
Auto Hold
The Auto Hold maintains the vehicle in a standstill even though the
brake pedal is not depressed after the driver brings the vehicle to a complete stop
by depressing the brake pedal.
The Auto Hold does not operate when:
| - |
The driver's seat belt is unfastened
and driver's door is opened |
| - |
The engine hood is opened |
| - |
The shift lever is in P (Park) |
For your safety, the Auto Hold automatically switches to EPB in such cases:
| - |
The driver's seat belt is unfastened
and driver's door is opened |
| - |
The engine hood is opened |
| - |
The vehicle is in a standstill
for more than 10 minutes |
| - |
The vehicle is standing on a
steep slope for a long period of time |
| - |
The vehicle moved several times
|
| 1. |
Set up
| (1) |
With the driver's door,
engine hood and trunk closed, fasten the driver's seat belt or depress
the brake pedal and then press the Auto Hold button. The white AUTO
HOLD indicator will come on and the system will be in the standby
position. |
| (2) |
When you stop the vehicle
completely by depressing the brake pedal, the AUTO HOLD indicator
changes from white to green. |
| (3) |
The vehicle will remain
stationary even if you release the brake pedal. |
| (4) |
If EPB is applied, Auto
Hold will be released and the indicator will change to white. |
|
| 2. |
Leaving If you want to release
it manually, pull the EPB switch while depressing the brake pedal. The AUTO
HOLD indicator changes from green to white and the system changes to the
standby position.
For your safety, release the Auto Hold operation manually if the vehicle
ahead is too close or during downhill driving. |
Components
1. EPB Unit
2. EPB Switch
3. Brake Caliper
4. EPB Warning Lamp
5. AUTO HOLD Lamp
...
Electronic Parking Brake (EPB). Components and Components Location