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2007 > 2.7L V6 GASOLINE >
description of ESP
Optimum driving safety now has a name : ESP, the Electronic Stability Control.
ESP recognizes critical driving conditions, such as panic reactions in dangerous situations, and stabilizes the vehicle
by wheel- individual braking and engine control intervention with no needfor actuating the brake or the gas pedal.
ESP adds a further function known as Active Yaw Control (AYC) to the ABS, TCS, EBD and ESP functions. Whereas
the ABS/TCS function controls wheel slip during braking and acceleration and, thus, mainly intervenes in the
longitudinal dynamics of the vehicle, active yaw control stabilizes the vehicle about its vertical axis.
This is achieved by wheel individual brake intervention and adaptation of the momentary engine torque with no need
for any action to be taken by the driver.
ESC essentially consists of three assemblies : the sensors, the electronic control unit and the actuators.
Of course, the stability control feature works under all driving and operating conditions. Under certain driving
conditions, the ABS/TCS function can be activated simultaneously with the ESP function in response to a command
by the driver.
In the event of a failure of the stability control function, the basic safety function, ABS, is still maintained.
DESCRIPTION OF ESP CONTROL
ESP system includes ABS/EBD, TCS and AYC (Active yaw control) function.
ABS/EBD function : The ECU changes the active sensor signal (current shift) coming from the four wheel sensors to
the square waveform.By using the input of above signals, the ECU calculates the vehicle speed and the acceleration
& deceleration of the four wheels.And, the ECU judges whether the ABS/EBD should be actuated or not.
TCS function prevents the wheel slip of drive direction by adding the brake pressure and engine torque reduction via
CAN communication.TCS function uses the wheel speed sensor signal to determine the wheel slip as far as ABS
function.
AYC function prevents unstable maneuver of the vehicle. To determine the vehicle maneuver, AYC function uses the
maneuver sensor signals(Yaw Rate Sensor, Lateral Acceleration Sensor, Steering Wheel Angle Sensor).If vehicle
maneuver is unstable (Over Steer or Under Steer), AYC function applies the brake pressure on certain wheel, and
send engine torque reduction signal by CAN.
After the key - on, the ECU continually diagnoses the system failure. (self- diagnosis)If the system failure is detected,
the ECU informs driver of the system failure through the BRAKE/ABS/ESP warning lamp. (fail- safe warning)
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VARIANT CODING
The HECU is programmed with a variant code based on the vehicle powertrain configuration. This variant code is
used to determine the appropriate ESP calculations. Variant code programming should be performed whenever an
HECU is replaced.
PROCEDURE OF VARIANT CODING1. Install a PCM(ECM & TCM)/ESP normally.
2. Connect the scan tool to the data link connector located underneath the dash panel.
3. Select vehicle name.
4. Select ANTI- LOCK BRAKE SYSTEM.
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If the warning lamp(ESP, EBD, ABS) is illuminated, follow the "Variant coding" again.
INPUT AND OUTPUT DIAGRAM
ESP OPERATION MODE
1.STEP 1
The ESP analyzes the intention of the driver.
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2.STEP 2
It analyzes the movement of the ESP vehicle.
3. STEP 3
he HECU calculates the required strategy, then actuates the appropriate valves and sents torque control requests
via CAN to maintain vehicle stability.
ESP OPERATION MODE
1.ESP Non- operation - Normal braking.
Inlet valve(EV)Outlet valve(AV)Pilot valve(USV)High pressure
switch valve(HSV)Pump motor
Normal braking OpenCloseOpenCloseOFF
EV : Inlet Valve
AV : Outlet Valve
LR : Rear left wheel
RF : Front right wheel
LF : Front left wheel
RR : Rear right wheel
PE : Pump motor
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USV : Pilot Valve
HSV : High pressure Switch Valve
2. ESP INCREASE MODE
Inlet valve(EV)Outlet valve(AV)Pilot valve(USV)High pressure
switch valve(HSV)Pump motor
Normal braking OpenCloseClose(Partial)OpenON(Motor speed
control)
EV : Inlet Valve
AV : Outlet Valve
LR : Rear left wheel
RF : Front right wheel
LF : Front left wheel
RR : Rear right wheel
PE : Pump motor
USV : Pilot Valve
HSV : High pressure Switch Valve
3. ESP HOLD MODE ( FR is only controlled.)
Inlet valve(EV)Outlet valve(AV)Pilot valve(USV)High pressure
switch valve(HSV)Pump motor
Normal braking CloseCloseClose(Partial)OpenON(Motor speed
low control)
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EV : Inlet Valve
AV : Outlet Valve
LR : Rear left wheel
RF : Front right wheel
LF : Front left wheel
RR : Rear right wheel
PE : Pump motor
USV : Pilot Valve
HSV : High pressure Switch Valve
4. ESP DECREASE MODE (FR is only controlled)
Inlet valve(EV)Outlet valve(AV)Pilot valve(USV)High pressure
switch valve(HSV)Pump motor
Normal braking CloseOpenClose(Partial)OpenON(Motor speed
low control)
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The active EBD warning lamp module indicates the self - test and failure status of the EBD. However, in case the
Parking Brake Switch is turned on, the EBD warning lamp is always turned on regardless of EBD functions. The EBD
warning lamp shall be on:a. During the initialization phase after IGN ON. (continuously 3 seconds).
b. When the Parking Brake Switch is ON or brake fluid level is low.
c. When the EBD function is out of order .
d. During diagnostic mode.
e. When the ECU Connector is seperated from ECU.
ESP Warning Lamp (ESP system)
The ESP warning lamp indicates the self - test and failure status of the ESP.
The ESP warning lamp is turned on under the following conditions :
a. During the initialization phase after IGN ON. (continuously 3 seconds).
b. In the event of inhibition of ESP functions by failure.
c. When driver turn off the ESP function by on/off switch.
d. During diagnostic mode.
ESC Function Lamp (ESC system)
The ESP function lamp indicates the self - test and operating status of the ESP.
The ESP Function lamp operates under the following conditions :
a. During the initialization phase after IGN ON. (continuously 3 seconds).
b. When the ESP control is operating. (Blinking - 2Hz)
ESP On/Off Switch (ESP system)
The ESP On/Off Switch shall be used to toggle the ESP function between On/Off states based upon driver input.
The On/Off switch shall be a normally open, momentary contact switch.
Initial status of the ESP function is on and the switch is used to request an ESC status change.
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2007 > 2.7L V6 GASOLINE >
FAILURE DIAGNOSIS
1.In principle, ESP and TCS controls are prohibited in case of ABS failure.
2. When ESP or TCS fails, only the failed system control is prohibited.
3. However, when the solenoid valve relay should be turned off in case of ESP failure, refer to the ABS fail- safe.
4. Information on ABS fail- safe is identical to the fail- safe in systems where ESP is not installed.
MEMORY OF FAIL CODE
1.It keeps the code as far as the backup lamp power is connected. (O)
2. It keeps the code as long as the HCU power is on. (X)
FAILURE CHECKUP
1.Initial checkup is performed immediately after the HECU power on.
2. Valve relay checkup is performed immediately after the IG2 ON.
3. It executes the checkup all the time while the IG2 power is on.
4. Initial checkup is made in the following cases.
(1) When no failure is detected
(2) When ABS and ESP are not in control.
(3) Initial checkup is not made after ECU power on.
(4) If the vehicle speed is over 5 mph(8 km/h) when the brake lamp switch is off.
(5) When the vehicle speed is over 24.8 mph(40 km/h).
5. Though, it keeps on checkup even if the brake lamp switch is on.
6. When performing ABS or ESP control before the initial checkup, stop the initial checkup and wait for the HECU
power input again.
7. Judge failure in the following cases.
(1) When the power is normal.
(2) From the point in which the vehicle speed reaches 4.9 mph(8 km/h) after HECU power on.
COUNTERMEASURES IN FAIL
1.Shut the system down and perform the following actions and wait for HECU power OFF.
2. Turn the valve relay off.
3. Do not perform any ABS/TCS/ESC functions until normal operating condition is restored.
WARNING LAMP ON
1.ABS warning lamp turns on when ABS is malfunctioning.
2. ESP operation lamp turns on when ESP is malfunctioning.
When power voltage and valve relay voltage are abnormal, input/output related failure judgment is not made.