Hyundai Elantra CN7: ESC (Electronic Stability Control) System

Seventh generation (CN7; 2021–2025) / Hyundai Elantra CN7 2021-2025 Workshop Manual / Brake System / ESC (Electronic Stability Control) System

Description and operation

Description of ESP

ESP recognizes critical driving conditions, such as panic reactions in dangerous situations, and stabilizes the vehicle by wheel-individual braking and engine control intervention.

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.

ESP essentially consists of three assemblies : the sensors, the electronic control unit and the actuators.

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 function.

ABS/EBD function : The ECU changes the active sensor signal (current shift) coming from the four wheel sensors to the square wave. 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)

Input and Output Diagram

ESP Operation Mode

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

2.	STEP 2 It analyzes the movement of the ESP 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.

ESP Hydraulic System Diagram

ESP Non-operation : Normal braking.

Solenoid Valve	Continuity	Valve	Motor Pump	TC Valve
IN (NO)	OFF	OPEN	OFF	OFF
OUT (NC)	OFF	CLOSE	OFF	OFF

ESP operation

Solenoid Valve		Continuity	Valve	Motor Pump	TC Valve
Understeering (Only inside of rear wheel)	IN (NO)	OFF	OPEN	ON	ON
Understeering (Only inside of rear wheel)	OUT (NC)	OFF	CLOSE
Oversteering (Only outside of front wheel)	IN (NO)	OFF	OPEN
Oversteering (Only outside of front wheel)	OUT (NC)	OFF	CLOSE

Warning Lamp Control

ABS Warning Lamp module

The active ABS warning lamp module 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 seperated from ECU.

–	Cluster lamp is ON when communication is impossible with CAN module.

EBD/Parking Brake Warning Lamp Module

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 shallbe 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 seperated from ECU.

–	Cluster lamp is ON when communication is impossible with CAN module.

ESP Function / Warning Lamp (ESP System)

The ESP function/warning lamp indicates the self-test and failure status of the ESP.

The ESP function/warning lamp is turned on under the following conditions :

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

–	When the ESP function is inhibited by system failure.

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

–	During diagnostic mode.(Except standard mode)

–	Cluster lamp is ON when communication is impossible with CAN module.

ESP OFF Lamp (ESP System)

The ESP Off lamp indicates the self-test and operating status of the ESP.

The ESP Off lamp operates under the following conditions :

–	During the initialization mode after IGN ON. (continuously 3 seconds).

–	ESP Off lamp is On when driver input the ESP Off switch.

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.Closed contacts switch the circuit to ignition.

Initial status of the ESP function is on and switch toggle the state.

Components and components location

Components

1. ESC control module (HECU)
2. Front wheel speed sensor

3. Rear wheel speed sensor
4. ESC OFF switch

Troubleshooting

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 far 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.

Countermeasures in Fail

1.	Turn the system down and perform the following actions and wait for HECU power OFF.

2.	Turn the valve relay off.

3.	Stop the control during the operation and do not execute any until the normal condition recovers.

Warning Lamp ON

1.	ESP warning lamp turn on for 3sec after IGN ON.

2.	ESP function lamp blinks when ESP Act.

3.	If ESP fail occured, ESP warning turns ON.

ESP OFF lamp turn on in case of

–	ESP Switch OFF

–	3sec after IGN ON

Standard Flow of Diagnostic Troubleshooting

Notes With Regard to Diagnosis

The phenomena listed in the following table are not abnormal.

Condition

Explanation

System check sound

When starting the engine, a thudding sound can sometimes be heard coming from inside the engine compartment. This is because the system operation check is being performed.

ABS operation sound

1)	Sound of the motor inside the ABS hydraulic unit operation (whine).

2)	Sound is generated along with vibration of the brake pedal (scraping).

3)	When ABS operates, sound is generated from the vehicle chassis due to repeated brake application and release (Thump : suspension; squeak : tires)

ABS operation (Long braking distance)

For road surfaces such as snow-covered and gravel roads, the braking distance for vehicles with ABS can sometimes be longer than that for other vehicles. Accordingly, advise the customer to drive safely on such roads by lowering the vehicle speed.

Inspection method

With the IGN OFF, set the IGN to ON position : If the ABS/Brake Warning Light illuminates and distinguishes after 3 seconds, the warning lamp and ABS system are all normal.

If the Warning Light does not illuminate when IGN is set to ON position

(1)	Remove the ABS ECU connecter (located in the engine room).

(2)	Set the IGN to ON position.

(3)	If the ABS/Brake Warning Light does not illuminate: The failure is related to the Warning Light. Check the instrument cluster and wiring.

(4)	If the ABS/Brake Warning Light illuminates and stays on :

The Warning Light is normal and judged to be failure of the VDC system. Inspect the VDC system using GDS.

If the Warning Light does not distinguish after its illumination when IGN is set to ON position.

(1)	Self-diagnose using GDS.

(2)	Record fault code.

(3)	Self-diagnose after erasing the fault code.

(4)	If the result of self-diagnosis is normal after erasing the fault code : Set the IGN to OFF, then to ON position and check whether the Warning Light operates normally.

(5)	If the result of self-diagnosis continues to display error after erasing the fault code : Check according to the inspection sheet of the fault code.

Even if the Warning Light and VDC system are all normal, erase all the memorized fault codes using GDS (if there is no memorized fault code, record the fault code).

1)	When removing or engaging all the connectors set the IGN to OFF position.

2)	During the driving test, record on the inspection sheet when the Warning Light illuminates or every time any event is occurred.

ABS Check Sheet

Problem Symptoms Table

Symptom

Suspect Area

ABS does not operate.

Only when 1 - 4 are all normal and the problem is still occurring, replace the HECU.

1)	Check the DTC reconfirming that the normal code is output.

2)	Power source circuit.

3)	Speed sensor circuit.

4)	Check the hydraulic circuit for leakage.

ABS does not operate intermittently.

Only when 1 - 4 are all normal and the problem is still occurring, replace the ABS actuator assembly.

1)	Check the DTC reconfirming that the normal code is output.

2)	Wheel speed sensor circuit.

3)	Stop lamp switch circuit.

4)	Check the hydraulic circuit for leakage.

Communication with GDS is not possible. (Communication with any system is not possible)

1)	Power source circuit

CAN line

Communication with GDS is not possible. (Communication with ABS only is not possible)

1)	Power source circuit

CAN line

HECU

When ignition key is turned ON (engine OFF), the ABS warning lamp does not light up.

1)	ABS warning lamp circuit

HECU

Even after the engine is started, the ABS warning lamp remains ON.

1)	ABS warning lamp circuit

HECU

•	During ABS operation, the brake pedal may vibrate or may not be able to be depressed. Such phenomena are due to intermittent changes in hydraulic pressure inside the brake line to prevent the wheels from locking and is not an abnormality.

•	Such phenomena are due to intermittent changes in hydraulic pressure inside the brake line to prevent the wheels from locking and is not an abnormality.

Detecting condition

Trouble Symptoms

Possible Cause

Brake operation varies depending on driving conditions and road surface conditions, so diagnosis can be difficult. However if a normal DTC is displayed, check the following probable cause. When the problem is still occurring, replace the ESP control module.

–	Faulty power source circuit

–	Faulty wheel speed sensor circuit

–	Faulty hydraulic circuit for leakage

–	Faulty HECU

Inspection procedures

DTC Inspection

1.	Connect the GDS with the data link connector and turn the ignition switch ON.

2.	Verify that the DTC code is output.

Is the DTC code output?

	▶ Check the power source circuit.
	▶ Erase the DTC and recheck using GDS.

Check the power source circuit

1.	Disconnect the connector from the ESP control module.

Turn the ignition switch ON, measure the voltage between terminal 29 of the ESP control module harness side connector and body ground.

Specification : approximately B+

Is the voltage within specification?

	▶ Check the ground circuit.
	▶ Check the harness or connector between the fuse (7.5A) in the engine compartment junction block and the ESP control module. Repair if necessary.

Check the ground circuit

1.	Disconnect the connector from the ESP control module.

Check for continuity between terminals 13, 38 of the ESP control module harness side connector and ground point.

Is there continuity?

	▶ Check the wheel speed sensor circuit.
	▶ Repair an open in the wire and ground point.

Check the wheel speed sensor circuit

1.	Refer to the DTC troubleshooting procedures.

Is it normal?

	▶ Check the hydraulic circuit for leakage.
	▶ Repair or replace the wheel speed sensor.

Check the hydraulic circuit for leakage

1.	Inspect leakage of the hydraulic lines.

Is it normal?

	▶ The problem is still occurring, replace the ESP control module.
	▶ Repair the hydraulic lines for leakage.

Detecting condition

Trouble Symptoms

Possible Cause

–	Faulty power source circuit

–	Faulty wheel speed sensor circuit

–	Faulty hydraulic circuit for leakage

–	Faulty HECU

Inspection procedures

DTC Inspection

1.	Connect the GDS with the data link connector and turn the ignition switch ON.

2.	Verify that the DTC code is output.

Is the DTC code output?

	▶ Check the wheel speed sensor circuit.
	▶ Erase the DTC and recheck using GDS.

Check the wheel speed sensor circuit

1.	Refer to the DTC troubleshooting procedures.

Is it normal?

	▶ Check the stop lamp switch circuit.
	▶ Repair or replace the wheel speed sensor.

Check the stop lamp switch circuit

1.	Check that stop lamp lights up when brake pedal is depressed and turns off when brake pedal is released.

Measure the voltage between terminal 23 of the ESP control module harness side connector and body ground when brake pedal is depressed.

Specification : approximately B+

Is the voltage within specification?

	▶ Check the hydraulic circuit for leakage.
	▶ Repair the stop lamp switch. Repair an open in the wire between the ESP control module and the stop lamp switch.

Check the hydraulic circuit for leakage

1.	Refer to the hydraulic lines.

2.	Inspection leakage of the hydraulic lines.

Is it normal?

	▶ The problem is still occurring, replace the ESP control module.
	▶ Repair the hydraulic lines for leakage.

Detecting condition

Trouble Symptoms

Possible Cause

Possible defect in the power supply system (including ground) for the diagnosis line.

–	An open in the wire

–	Poor ground

–	Faulty power source circuit

Inspection procedures

Check The Power Supply Circuit For The Diagnosis

Measure the voltage between terminal 16 of the data link connector and body ground.

Specification : approximately B+

Is voltage within specification?

	▶ Check the ground circuit for the diagnosis.
	▶ Repair an open in the wire. Check and replace fuse from the engine compartment junction block.

Check the ground circuit for the diagnosis

Check for continuity between terminal 4 of the data link connector and body ground.

Is there continuity?

▶ Repair an open in the wire between terminal 4 of the data link connector and ground point.

Detecting condition

Trouble Symptoms

Possible Cause

When communication with GDS is not possible, the cause may be probably an open in the HECU power circuit or an open in the diagnosis output circuit.

–	An open in the wire

–	Faulty HECU

–	Faulty power source circuit

Inspection procedures

Check for Continuity in the CAN Line

1.	Disconnect the connector from the ESP control module.

2.	Check for continuity between terminals 26, 14 of the ESP control module connector and 3, 11 of the data link connector.

Is there continuity?

	▶ Check the power source of ESP control module.
	▶ Repair an open in the wire.

Check the power source of ESP control module

1.	Disconnect the connector from the ESP control module.

Turn the ignition switch ON, measure the voltage between terminal 29 of the ESP control module harness side connector and body ground.

Specification : approximately B+

Is voltage within specification?

	▶ Check for poor ground.
	▶ Check the harness or connector between the fuse (10A) in the engine compartment junction block and the ESP control module.Repair if necessary.

Check for poor ground

1.	Check for continuity between terminal 4 of the data link connector and ground point.

Is the electric current applied between groundings?

	▶ Replace the ESP control module and recheck.
	▶ Repair an open in the wire or poor ground

Detecting condition

Trouble Symptoms

Possible Cause

When current flows in the HECU the ABS warning lamp turns from ON to OFF as the initial check. Therefore if the lamp does not light up, the cause may be an open in the lamp power supply circuit, a blown bulb, an open in the both circuits between the ABS warning lamp and the HECU, and the faulty HECU.

–	Faulty ABS warning lamp bulb

–	Blown fuse is related to ABS in the engine compartment junction block

–	Faulty ABS warning lamp damaged

–	Faulty ABS warning lamp module

–	Faulty HECU

Inspection procedures

Problem verification

1.	Disconnect the connector from the ESP control module and turn the ignition switch ON.

Does the ABS warning lamp light up?

	▶ Inspectagain after replacing the ESP HECU.
	▶ Check the power source for the ABS warning lamp.

Check the power source for the ABS warning lamp

1.	Disconnect the instrument cluster connector (M08) and turn the ignition switch ON.

Measure the voltage between terminal (M08) 39 of the cluster harness side connector and body ground.

Specification : approximately B+

Is voltage within specification?

	▶ Check the CAN circuit resistance for ABS warning lamp.
	▶ Check for blown fuse.

Check the CAN circuit resistance for ABS warning lamp

1.	Disconnect the instrument cluster connector (M08) and turn the ignition switch OFF.

Measure the resistance between terminal (M08) 32 and 33 of the cluster harness side connector.

Specification : 60Ω

Is resistance within specification?

	▶ Repair ABS warning lamp bulb or instrument cluster assembly.
	▶ Check the CAN circuit wiring for ABS warning lamp.

Check the CAN circuit wiring for ABS warning lamp

1.	Disconnect the instrument cluster connector (M08) and ESP HECU connector, and then turn the ignition switch OFF.

Check for continuity between terminal (M08) 32 of the cluster harness side connector and terminal 26 of ESP HECU harness side.

Check for continuity between terminal (M08) 33 of the cluster harness side connector and terminal 14 of ESP HECU harness side.

Specification : Below 1Ω

Is resistance within specification?

	▶ Repair short of wiring between terminal 26, 14 of ESP HECU harness connector and ABS warning lamp module.
	▶ Repair open of wiring between terminal 26, 14 of ESP HECU harness connector and ABS warning lamp module.

Detecting condition

Trouble Symptoms

Possible Cause

If the HECU detects trouble, it lights the ABS warning lamp while at the same time prohibiting ABS control. At this time, the HECU records a DTC in memory. Even though the normal code is output, the ABS warning lamp remains ON, then the cause may be probably an open or short in the ABS warning lamp circuit.

–	An open in the wire

–	Faulty instrument cluster assembly

–	Faulty ABS warning lamp module

–	Faulty HECU

Inspection procedures

Check DTC Output

1.	Connect the GDS to the 16P data link connector located behind the driver's side kick panel.

2.	Check the DTC output using GDS.

Is DTC output?

	▶ Perform the DTC troubleshooting procedure (Refer to DTC troubleshooting).
	▶ Check the CAN circuit resistance for ABS warning lamp.

Check the CAN circuit resistance for ABS warning lamp

1.	Disconnect the instrument cluster connector (M08) and turn the ignition switch OFF.

Measure the resistance between terminal (M08) 32 and 33 of the cluster harness side connector.

Specification : 60Ω

Is resistance within specification?

	▶ Repair ABS warning lamp bulb or instrument cluster assembly.
	▶ Check the CAN circuit wiring for ABS warning lamp.

Check the CAN circuit wiring for ABS warning lamp

1.	Disconnect the instrument cluster connector (M08) and ESP HECU connector, and then turn the ignition switch OFF.

Check for continuity between terminal (M08) 32 of the cluster harness side connector and terminal 26 of ESP HECU harness side.

Check for continuity between terminal (M08) 33 of the cluster harness side connector and terminal 14 of ESP HECU harness side.

Specification : Below 1Ω

Is resistance within specification?

	▶ Repair short of wiring between terminal 26, 14 of ESP HECU harness connector and ABS warning lamp module.
	▶ Repair open of wiring between terminal 26, 14 of ESP HECU harness connector and ABS warning lamp module.

Schematic diagrams

Terminal Function

[EPB None Apply]

PIN No	Desciption	Current
PIN No	Desciption	max	min
1	Voltage supply for pump motor	40A	10 MΩ
2	Hazard switch	1.2 mA	250 MΩ
3	-
4	C-CAN HIGH	100 mA	250 MΩ
5	C-CAN LOW	100 mA	250 MΩ
6
7	P-CAN LOW	100 mA	250 MΩ
8	P-CAN High	100 mA	250 MΩ
9	Wheel speed sensor power voltage (RL)	100 mA	250 MΩ
10	Wheel speed sensor power voltage (RR)	100 mA	250 MΩ
11	Wheel speed sensor power voltage (FR)	100 mA	250 MΩ
12	Wheel speed sensor power voltage (FL)	100 mA	250 MΩ
13	Recirculation pump ground	40A	10 MΩ
14	-
15	Clutch Switch (MT Only)	1.2 mA	250 MΩ
16	DBC Switch	1.2 mA	250 MΩ
17	ESP Switch	1.2 mA	250 MΩ
18	-
19	Parking brake switch	1.2 mA	250 MΩ
20	-
21	Wheel speed sensor ground (RL)	40 mA	250 MΩ
22	Wheel speed sensor ground (RR)	40 mA	250 MΩ
23	Wheel speed sensor ground (FR)	40 mA	250 MΩ
24	Wheel speed sensor ground (FL)	40 mA	250 MΩ
25	Voltage supply for solenoid valves	30A	10 MΩ
26	-
27	-
28	-
29	-
30	Brake lamp switch	1.2 mA	250 MΩ
31	-
32	IGN 1	10mA	50MΩ
33	-
34	HAC / BLA signal output	1.2 mA	250 MΩ
35	ESS signal output	1.2 mA	250 MΩ
36	-
37	Wheel speed sensor output (FR)	50 mA	250 MΩ
38	Ground for solenoid valves and ECU	30A	10 MΩ

[EPB Apply]

PIN No	Desciption	Current	Permit resistance
1	Voltage supply for pump motor	60A	10 MΩ
2	RR EPB motor power	15A	10 MΩ
3	RR EPB motor ground	15A	10 MΩ
4	-	-	-
4	Clutch stroke sensor signal	-	-
5	Local CAN High	40A	250 MΩ
6	Electric parking brake signal 1	20 mA	250 MΩ
7	Electric parking brake signal 2	20 mA	250 MΩ
8	Electric parking brake signal 3	20 mA	250 MΩ
9	Electric parking brake signal 4	20 mA	250 MΩ
10	-	-	-
11	-	-	-
12	RL EPB motor ground	15A	10 MΩ
13	RL EPB motor power	15A	10 MΩ
14	Valves & ECU ground	40A	10 MΩ
15	DBC switch signal	1.2 mA	250 MΩ
16	-
17	ESP OFF switch signal	1.2 mA	250 MΩ
18	N Signal	100 mA	250 MΩ
19	Local CAN High	100 mA	250 MΩ
20	Local CAN Low	100 mA	250 MΩ
21	-
22	P-CAN LOW	100 mA	250 MΩ
23	P-CAN High	100 mA	250 MΩ
24	-
25	Wheel speed sensor supply voltage (RL)	150 mA	250 MΩ
26	Wheel speed sensor supply voltage (RR)	150 mA	250 MΩ
27	Wheel speed sensor supply voltage (FR)	150 mA	250 MΩ
28	Wheel speed sensor supply voltage (FL)	150 mA	250 MΩ
29	-
30	Voltage supply for solenoid valves	40A	10 MΩ
31	-
32	-
33	-
34	Auto holding ON/OFF switch signal	1.2 mA	250 MΩ
35	Brake light switch	1.2 mA	250 MΩ
36	HAC / BLA signal output	1.2 mA	250 MΩ
37	IGN 1	10 mA	50 MΩ
38	ESS signal output	1.2 mA	250 MΩ
39	-
40	-
41	Wheel speed sensor ground (RL)	40 mA	250 MΩ
42	Wheel speed sensor ground (RR)	40 mA	250 MΩ
43	Wheel speed sensor ground (FR)	40 mA	250 MΩ
44	Wheel speed sensor ground (FL)	40 mA	250 MΩ
45	Wheel speed sensor power (FR)	50 mA	250 MΩ
46	Recirculation pump ground	60A	10 MΩ

ESC (Electronic Stability Control) Module

Components and components location

Components

[LHD]

1. Front - right (FR)
2. Rear - left (RL)
3. Rear - right (RR)
4. Front - left (FL)

5. MC2
6. MC1
7. ABS control module (HECU)
8. Bracket

[RHD]

1. Front - right (FR)
2. Rear - left (RL)
3. Rear - right (RR)
4. Front - left (FL)

5. MC2
6. MC1
7. ABS control module (HECU)
8. Bracket

Repair procedures

Removal

[LHD]

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

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

Separate the brake tubes from the HECU by unlocking the nuts (6-ea) couterclockwise using 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)

Loosen the ABS control module mounting nut and then remove the ABS control module (A) from the vehicle.

Tightening torque :

16.7 - 25.5 N.m (1.7 - 2.6 kgf.m, 12.3 - 18.8 lb-ft)

5.	Separate the bracket (B) after remove the mounting bolt from the HECU (A).

[RHD]

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

2.	Remove the battery and battery tray. (Refer to Engine Electrical System - "Battery")

3.	Pull up the lock of the HECU connector and then disconnect the connector (A).

Separate the brake tubes from the HECU by unlocking the nuts (6-ea) couterclockwise using 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)

Loosen the ABS control module mounting nut and then remove the ESC control module (A) from the vehicle.

Tightening torque :

16.7 - 25.5 N.m (1.7 - 2.6 kgf.m, 12.3 - 18.8 lb-ft)

6.	Separate the bracket (B) after remove the mounting bolt from the HECU (A).

Installation

1.	To install, reverse the removal procedure.

2.	After installation, bleed the brake system. (Refer to Brake System - "Brake Bleeding Prcoedures")

Adjustment

Perform diagnostic procedure by using diagnostic device as shown below.

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

2.	Select the "vehicle model" and "ESP/ESC" on GDS vehicle selection screen, then select OK. [Variant Code Reset] [Variant Coding] [Longitudinal G Sensor Calibration]

ESC OFF Switch

Description and operation

Description

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

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

Repair procedures

Removal

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

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

3.	Loosen the screw and than removing the ESC OFF switch (A).

4.	Disconnect the crash pad lower switch connector (A).

5.	Remove the VDC OFF switch (A) after loosening screw.

Front Wheel Speed Sensor

Components and components location

Components

1. Front wheel speed sensor

2. Front wheel speed sensor connector

Repair procedures

Removal

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

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

Remove the rear wheel and tire (A) from the rear hub.

•	Be careful not to damage the hub bolts when removing the front wheel and tire (A).

4.	Remove the front wheel guard. (Refer to Body - "Front Wheel Guard")

5.	Disconnect the front wheel speed sensor connector (A) and then remove the fixing clip (B).

Remove the front 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)

Remove the wheel speed sensor (A) from the Knuckle after loosening the mounting bolt.

Tightening torque :

7.8 - 11.8 N.m (0.8 - 1.2 kgf.m, 5.8 - 8.7 lb-ft)

Installation

1.	To install, reverse the removal procedure.

Inspection

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 100Ω resister must be used as shown.

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 : 0.03 - 3,000 Hz

Rear Wheel Speed Sensor

Components and components location

Components

[Rear torsion beam disc brake type]

1. Rear wheel speed sensor

2. Rear wheel speed sensor connector

[Rear multi link disc brake type]

1. Rear wheel speed sensor

2. Rear wheel speed sensor connector

[Rear drum brake type]

1. Rear wheel speed sensor

2. Rear wheel speed sensor connector

Repair procedures

Removal

[Rear torsion beam disc brake type]

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

Remove the rear wheel and tire (A) from the rear hub.

•	Be careful not to damage the hub bolts when removing the front wheel and tire (A).

3.	Remove the rear brake caliper. (Refer to Brake System - "Rear Disc Brake")

Remove the rear brake disc (A).

Tightening torque :

4.9 - 5.9 N.m (0.5 - 0.6 kgf.m, 3.6 - 4.3 lb-ft)

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

Remove the hub bearing assembly (A) after loosening the mounting bolts.

Tightening torque :

49.0 - 58.8 N.m (5.0 - 6.0 kgf.m, 36.2 - 43.4 lb-ft)

[Rear multi link disc brake type]

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

Remove the rear wheel and tire (A) from the rear 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.	Remove the rear brake caliper. (Refer to Brake System - "Rear Disc Brake")

Remove the rear brake disc (A) after loosening the mounting screw.

Tightening torque :

4.9 - 5.9 N.m (0.5 - 0.6 kgf.m, 3.6 - 4.3 lb-ft)

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

Remove the hub bearing assembly after loosening the hub bearing mounting bolts (A).

Tightening torque :

88.3 - 107.9 N.m (9.0 - 11.0 kgf.m, 65.1 - 79.6 lb-ft)

[Rear drum brake type]

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

Remove the rear wheel and tire (A) from the rear hub.

•	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 screw and then remove the rear drum brake (A).

5.	Loosen the hub mounting bolts and then remove the hub (A) from the torsion beam.

Replacement

1.	Remove the rear wheel hub bearing assembly. (Refer to Driveshaft and Axle - "Rear Hub - Carrier")

Fix the rear hub bearing assembly (A) on the vise.

•	When fixing on the vise, use a cloth not to be damaged the hub bearing assembly.

•	Be careful if excessive force for fixing on the vise may damage the hub bearing assembly.

3.	Check the direction of the sensor cap (A).

Remove the sensor cap by hammering on a gap between sensor cap and hub bearing assembly using a scraper (A).

•	In order to widen the gap little by little, hammering around the bearing cap 10-20 times.

•	When removing the sensor cap, remove it in a straight direction not to damage the tone wheel or encoder.

Check if distorted or damaged the tone wheel or encoder (A).

•	Check if damaged the tone wheel or encoder after removing the sensor cap and replace the hub bearing if it was deformed.

•	If the tone wheel is deformed, it may trigger the MIL ON or other problems.

Position the sensor cap to the same direction of sensor cap connector (A) as you checked before removing.

•	Before installing the sensor cap, do not let any foreign material and contaminant into the hub bearing (A) assembly.

Install the sensor cap (A) with the special service tool (09527-AL300).

•	Hammer until there is no gap between the SST and hub bearing assembly and install the sensor cap.

•	Be careful not to tilt to one side when installing the sensor cap as it may damage the tone wheel or encoder.

•	When sensor cap installation, hammering it until the gap disappeared between the sensor cap and hub bearing assembly.

8.	Install the rear wheel hub bearing assembly. (Refer to Driveshaft and Axle - "Rear Hub - Carrier")

Installation

1.	To install, reverse the removal procedure.

Inspection

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 100Ω resister must be used as shown.

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 - 2,500 Hz

Emergency Signal System

Description and operation

Description

Introduction of Quick Brake Warning System (ESS)

In case of quick brake by driver, the brake lamp or turn signal is blinked to warn against the vehicle at rear.

Basic function (Blinking the brake lamp/emergency lamp)

–	Operation condition : In case of quick brake or operation of ABS above in a certain speed

–	Releasing condition : In case of stopping the quick brake or releasing the ABS operation

Additional function (Blinking the turn signal)

–	Operation condition : In case of quick brake in low speed

–	Releasing condition : Releasing at the start of driving

System Configuration

ESS Circuit Diagram

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