Components and Components Location

Components

1. ESC Control Module(HECU) 2. Front Wheel Speed Sensor 3. Rear Wheel Speed Sensor

4. ABS Warning lamp 5. EBD / Parking brake warning lamp

Description and Operation

Description of ESC

Optimum driving safety now has a name : ESC, the Electronic Stability Program.

ESC 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.

ESC adds a further function known as Active Yaw Control (AYC) to the ABS, TCS, EBD and ESC 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 ESC function in rESConse 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 ESC Control

ESC 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/ESC warning lamp. (fail-safe warning)

Input and Output Diagram

ESC Operation Mode

1.	STEP 1 The ESC analyzes the intention of the driver.

2.	STEP 2 It analyzes the movement of the ESC vehicle.

3.	STEP 3 The HECU calculates the required strategy, then actuates the appropriate valves and sents torque control requests via CAN to maintain vehicle stability.

ESC Operation Mode

1.

ESC Non-operation-Normal braking. Inlet valve(IV) Outlet valve(OV) Traction Control Valve(TCV) High pressure switch valve(HSV) Return pump Normal braking Open Close Open Close OFF • IV : Inlet Valve • OV : Outlet Valve • RL : Rear left wheel • FR : Front right wheel • FL : Front left wheel • RR : Rear right wheel • RP : Return pump • TCV : Traction Control Valve • HSV : High pressure Switch Valve

2.

ESC Increase Mode Inlet valve(IV) Outlet valve(OV) Traction Control Valve(TCV) High pressure switch valve(HSV) Return pump Normal braking Open Close Close(Partial) Open ON(Motor speed control) • IV : Inlet Valve • OV : Outlet Valve • RL : Rear left wheel • FR : Front right wheel • FL : Front left wheel • RR : Rear right wheel • RP : Return pump • TCV : Traction Control Valve • HSV : High pressure Switch Valve

3.

ESC Hold Mode ( FR is only controlled.) Inlet valve(IV) Outlet valve(OV) Traction Control Valve(TCV) High pressure switch valve(HSV) Return pump Normal braking Close Close Close(Partial) Open OFF • IV : Inlet Valve • OV : Outlet Valve • RL : Rear left wheel • FR : Front right wheel • FL : Front left wheel • RR : Rear right wheel • RP : Return pump • TCV : Traction Control Valve • HSV : High pressure Switch Valve

4.

ESC Decrease Mode (FR is only controlled) Inlet valve(IV) Outlet valve(OV) Traction Control Valve(TCV) High pressure switch valve(HSV) Return pump Normal braking Close Open Close(Partial) Open ON(Motor speed low control) • IV : Inlet Valve • OV : Outlet Valve • RL : Rear left wheel • FR : Front right wheel • FL : Front left wheel • RR : Rear right wheel • RP : Return pump • TCV : Traction Control Valve • HSV : High pressure Switch Valve

[Super vision]

[General]

ABS Warning lamp

The active ABS warning lamp indicates the self-test and failure status of the ABS. The ABS warning lamp shall be on:

-	During the initialization phase after IGN ON. (continuously 3 seconds).

-	In the event of inhibition of ABS functions by failure.

-	During diagnostic mode.

-	When the ECU Connector is separated from ECU.

EBD/Parking brake warning lamp

The active EBD warning lamp 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:

-	During the initialization phase after IGN ON. (continuously 3 seconds).

-	When the Parking Brake Switch is ON or brake fluid level is low.

-	When the EBD function is out of order .

-	During diagnostic mode.

-	When the ECU Connector is separated from ECU.

ESC Function/Warning Lamp (ESC System)

The ESC Function/Warning lamp indicates the self-test and failure status of the ESC.

The ESC Function/Warning lamp operates under the following conditions :

-	During the initialization phase after IGN ON. (continuously 3 seconds).

-	In the event of inhibition of ESC functions by failure.

-	During dignostic mode.

-	When the ESC control is operating. (Blinking - 2Hz)

ESC OFF Lamp (ESC system)

The ESC OFF lamp indicates the self-test and operating status of the ESC.

The ESC OFF lamp is turned on under the following conditions :

-	During the initialization phase after IGN ON. (continuously 3 seconds).

-	When driver turn off the ESC function by on/off switch.

ESC On/Off Switch (ESC system)

The ESC On/Off Switch shall be used to toggle the ESC 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 ESC function is on and the switch is used to request an ESC status change.

Schematic Diagrams

Schematic Diagrams

Terminal Function

Wire No.	Designation	Current
		max	min
13	Ground for recirculation pump	39 A	10 A
1	Voltage supply for pump motor	39 A	10 A
25	Voltage supply for solenoid valves	15 A	2 A
38	Ground for solenoid valves andECU	15 A	2 A
22	Signal wheel speed sensor (FL)	16.8 mA	5.9 mA
33	Voltage supply for the active wheel speed sensor(RL)	16.8 mA	5.9 mA
19	Voltage supply for the active wheel speed sensor(RR)	16.8 mA	5.9 mA
18	Voltage supply for the active wheel speed sensor(FR)	16.8 mA	5.9 mA
6	Signal wheel speed sensor (FR)	16.8 mA	5.9 mA
14	C-CAN LOW	30 mA	20 mA
34	Voltage supply for the active wheel speed sensor(FL)	16.8 mA	5.9 mA
20	Signal wheel speed sensor (RL)	16.8 mA	5.9 mA
32	Voltage for HECU (IGN)	1 A	500 mA
31	Signal wheel speed sensor (RR)	16.8 mA	5.9 mA
30	Brake light switch	10 mA	5 mA
26	C-CAN HIGH	30 mA	20 mA
27	Wheel speed sensor output	Open Draim	-
8	ESC switch	10 mA	5 mA
23	Clutch switch (MT Only)	10 mA	5 mA
10	Parking Brake switch	10 mA	5 mA
21	L-CAN LOW	30 mA	20 mA
9	L-CAN HIGH	30 mA	20 mA

Repair procedures

Inspection

ESC System Bleeding

This procedure should be followed to ensure adequate bleeding of air and filling of the ESC unit, brake lines and master cylinder with brake fluid.

1.	Remove the reservoir cap and fill the brake reservoir with brake fluid. • If there is any brake fluid on any painted surface, wash it off immediately. • When pressure bleeding, do not depress the brake pedal. • Recommended fluid........ DOT3 or DOT4

2.	Connect a clear plastic tube to the wheel cylinder bleeder plug and insert the other end of the tube into a half filled clear plastic bottle.

3.	Connect the GDS to the data link connector located underneath the dash panel.

4.	Select and operate according to the instructions on the GDS screen • You must obey the maximum operating time of the ESC motor with the GDS to prevent the motor pump from burning. 1. Select vehicle name. 2. Select ABS/ESC system. 3. Select HCU air bleeding mode.

5.	Pump the brake pedal several times, and then loosen the bleeder screw until fluid starts to run out without bubbles. Then close the bleeder screw (A). [Front] [Rear Disc Brake] [Rear Durm Brake]

6.	Repeat the procedure for wheel in the sequence shown below until air bubbles no longer appear in the fluid.

7.	Refill the master cylinder reservoir to MAX(upper) level line.

Troubleshooting

Failure Diagnosis

1.	In principle, ESC and TCS controls are prohibited in case of ABS failure.

2.	When ESC or TCS fails, only the failed system control is prohibited.

3.	However, when the solenoid valve relay should be turned off in case of ESC failure, refer to the ABS fail-safe.

4.	Information on ABS fail-safe is identical to the fail-safe in systems where ESC 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 ESC 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 ESC 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.	ESC function/ warning lamp turns on when ESC is malfunctioning.

When power voltage and valve relay voltage are abnormal, input/output related failure judgment is not made.

ESC Control Unit Components and Components Location

Components

1. Front - right tube 2. Rear - left tube 3. Rear - right tube 4. Front - left tube

5. MC SEC 6. MC PRI 7. ESC control module(HECU) 8. Bracket

ESC Control Unit Repair procedures

Removal

1.	Turn the ignition switch OFF and then disconnect the negative (-) battery cable.

2.	Pull up the lock of the HECU connector (A) , then disconnect the connector.

3.

Remove the brake fluid from the master cylinder reservoir with a syringe. • Be sure to completely remove foreign substances from around brake fluid reservoir and cap before opening the reservoir cap. If not, it may cause contamination of brake fluid and deterioration in braking performance. • Do not spill brake fluid on the vehicle, it may damage the paint; if brake fluid does contact the paint, wash it off immediately with water.

4.	Disconnect the brake tubes from the HECU by unlocking the nuts counterclockwise with a spanner. Tightening torque: 12.7 ~ 16.7 N.m (1.3 ~ 1.7 kgf.m, 9.4 ~ 12.3 lb-ft) Tightening torque: 18.6 ~ 22.6 N.m (1.9 ~ 2.3 kgf.m. 13.7 ~ 16.6 lb-ft)

5.	Disconnect connectors and then remove the bracket.

6.	Loosen the HECU bracket bolts (A), then remove HECU and bracket. Tightening torque : 16.7 ~ 25.5 N.m (1.7 ~ 2.6 kgf.m, 12.3 ~ 18.8 lb-ft)

7.	Remove the 3 bolts, then remove the bracket from HECU. Tightening torque : 7.8 ~ 9.8 N.m (0.8 ~ 1.0 kgf.m, 5.8 ~ 7.2 lb-ft)

Installation

1.	To install, reverse the removal procedure.

2.	Tighten the HECU mounting bolts and nuts to the specified torque.

3.	After installation, bleed the brake system. (Refer to ESP(Electronic Stability Program) System - "ESP System Bleeding")

4.	Conduct the Variant coding.

5.	Conduct the Auto Detected Sensor Calibration.

6.	Conduct the Longitudinal G Sensor Calibration.

Adjustment

Diagnosis procedure by using diagnostic device

As manual for diagnosis methods by using diagnosis device, the main contents are as follows:

Connect self-diagnosis connector(16pins) located in the lower of driver side crash pad to self-diagnosis device, and then turn the self-diagnosis device after key is ON.

Select the "vehicle model" and "ABS/ESC" on GDS vehicle selection screen, then select OK.

[Variant Coding]

[Auto Detected Sensor Calibration]

[Longitudinal G Sensor Calibration]

ESC OFF Switch Description and Operation

Description

1.	The ESC OFF switch is for the user to turn off the ESP system.

2.	The ESC OFF lamp is on when ESP OFF switch is engaged.

ESC OFF Switch Repair procedures

Removal

1.	Turn ignition switch OFF and disconnect the negative (-) battery cable.

2.	Remove the crash pad lower panel. (Refer to Body - "Crash Pad")

3.	Remove the side crash pad switch.

4.	Disconnect the ESC OFF switch connector.

5.	Check the continuity between the switch terminals as the ESC OFF switch is engaged.

Front Wheel Speed Sensor Components and Components Location

Components

1. Front wheel speed sensor

2. Front wheel speed sensor connector

Front Wheel Speed Sensor Repair procedures

Removal

1.	Loosen the wheel nuts slightly. Raise the vehicle, and make sure it is securely supported.

2.	Remove the front wheel and tire (A) from front hub . Tightening torque: 107.9 ~ 127.5 N.m (11.0 ~ 13.0 kgf.m, 79.6 ~ 94.0 lb-ft) • Be careful not to damage the hub bolts when removing the front wheel and tire (A).

3.	Loosen the mounting holt and then remove the wheel speed sensor cable from the strut assembly. Tightening torque : 8.8 ~ 13.7 N.m(0.9 ~ 1.4 kgf.m, 6.5 ~ 10.1 lb-ft)

4.	Remove the wheel speed sensor cable braket bolt (A). Tightening torque: 7.8 ~ 11.8 N.m (0.8 ~ 1.2 kgf.m, 5.8 ~ 8.7 lb-ft)

5.	Remove the front wheel guard.

6.	Disconnect the wheel speed sensor connector (A) and then remove it.

7.	Loosen the bolt and then remove the wheel speed sensor (A). Tightening torque: 7.8 ~ 11.8 N.m (0.8 ~ 1.2 kgf.m, 5.8 ~ 8.7 lb-ft)

8.	To install, reverse the removal procedure.

Inspection

1.	Measure the output voltage between the terminal of the wheel speed sensor and the body ground. • In order to protect the wheel speed sensor, when measuring output voltage, a 100 ? resister must be used as shown.

2.	Compare the change of the output voltage of the wheel speed sensor to the normal change of the output voltage as shown below. V_low : 0.59V ~ 0.84V V_high : 1.18V ~ 1.68V Frequency range : 1 ~ 2,500Hz

Rear Wheel Speed Sensor Components and Components Location

Components

1. Front wheel speed sensor

2. Front wheel speed sensor cable

Rear Wheel Speed Sensor Repair procedures

Removal

1.	Loosen the wheel nuts slightly. Raise the vehicle, and make sure it is securely supported.

2.	Remove the rear wheel and tire (A) from front hub . Tightening torque: 107.9 ~ 127.5 N.m (11.0 ~ 13.0 kgf.m, 79.6 ~ 94.0 lb-ft) • Be careful not to damage the hub bolts when removing the rear wheel and tire (A).

3.	Disconnect the rear wheel speed sensor connector(A).

4.	Loosen the mounting bolt and then remove the wheel speed sensor cable bracket (A) and (B). Tightening torque : A : 8.8 ~ 13.7 N.m (0.9 ~ 1.4 kgf.m, 6.5 ~ 10.1 lb-ft) B : 7.8 ~ 11.8 N.m (0.8 ~ 1.2 kgf.m, 5.8 ~ 8.7 lb-ft)

5.	Remove the rear seat back. (Refer to Body - "Seat")

6.	Disconnect the rear wheel speed sensor connector (A), and than remove the rear wheel speed sensor.

7.	To install, reverse the removal procedure.

Inspection

1.	Measure the output voltage between the terminal of the wheel speed sensor and the body ground. • In order to protect the wheel speed sensor, when measuring output voltage, a 100 ? resister must be used as shown.

2.	Compare the change of the output voltage of the wheel speed sensor to the normal change of the output voltage as shown below. V_low : 0.59V ~ 0.84V V_high : 1.18V ~ 1.68V Frequency range : 1 ~ 2,500Hz