Components and Components Location

Components

1. ABS 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

This specification applies to HCU(Hydraulic Control Unit) and ECU(Electronic Control Unit) of the HECU.(Hydraulic and Electronic Control Unit)

This specification is for the wiring design and installation of ABS ECU.

This unit has the functions as follows.

-	Input of signal from the wheel speed sensors attached to each wheel.

-	Control of braking force.

-	Failsafe function.

-	Self diagnosis function.

-	Interface with the external diagnosis tester.

Installation Position : Engine Compartment

-	Brake tube length from Master cylinder port to HECU inlet port should be max. 1m

-	The position should not be close to the engine block and not lower than the wheel.

Operation

The ECU shall be put into operation by switching on the operating voltage (IGN).

On completion of the initialization phase, the ECU shall be ready for operation.

In the operating condition, the ECU shall be ready, within the specified limits (voltage and temperature), to process the signals offered by the various sensors and switches in accordance with the control algorithm defined by the software and to control the hydraulic and electrical actuators.

Wheel Sensor Signal Processing

The ECU shall receive wheel speed signal from the four active wheel sensors.

The wheel signals are converted to voltage signal by the signal conditioning circuit after receiving current signal from active wheel sensors and given as input to the MCU.

Solenoid Valve Control

When one side of the valve coil is connected to the positive voltage that is provided through the valve relay and the other side is connected to the ground by the semiconductor circuit, the solenoid valve goes into operation.

The electrical function of the coils are always monitored by the valve test pulse under normal operation conditions.

Voltage Limits

-	Overvoltage When overvoltage is detected(above 16.8 V), the ECU switches off the valve relay and shuts down the system. When voltage is returned to operating range, the system goes back to the normal condition after the initialization phase.

-	Undervoltage In the event of undervoltage(below 9.3 V), ABS control shall be inhibited and the warning lamp shall be turned on. When voltage is returned to operating range, the warning lamp is switched off and ECU returns to normal operating mode.

Pump Motor Checking

The ECU performs a pump motor test at a speed of 30km/h once after IGN is switched on.

Diagnostic Interface

Failures detected by the ECU are encoded on the ECU, stored in a EEPROM and read out by diagnostic equipment when the ignition switch is turned on.

The diagnosis interface can also be used for testing the ECU during production of the ECU and for actuating the HCU (Air-bleeding line or Roll and Brake Test line).

Warning Lamp Module

[Super vision]

[General]

1.

ABS Warning Lamp The active ABS warning lamp indicates the selftest and failure status of the ABS. The ABS warning lamp shall be on: A. During the initialization phase after IGN ON. (continuously 3 seconds). B. In the event of inhibition of ABS functions by failure. C. During diagnostic mode. D. When the ECU Connector is separated from ECU.

2.

EBD/Parking brake Warning Lamp The active EBD warning lamp indicates the selftest 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 separated from ECU.

ABS Control

1.	Normal Braking without ABS Inlet valve(IV) Outlet valve(OV) Return pump Operation 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

2.	Decrease Mode Inlet valve(IV) Outlet valve(OV) Return pump Operation Close 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

3.	Hold Mode Inlet valve(IV) Outlet valve(OV) Return pump Operation Close Close 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

4.	Increase Mode Inlet valve(IV) Outlet valve(OV) Return pump Operation Open Close 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

Schematic Diagrams

Schematic Diagrams

Termianal 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 and ECU	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	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	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	CAN HIGH	30 mA	20 mA
27	Wheel speed sensor output	Open Draim

Repair procedures

Inspection

ABS 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

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.
Diagnosis detection conditions can vary depending on the diagnosis code. When checking the trouble symptom after the diagnosis code has been erased, ensure that the requirements listed in "Comment" are met.

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 2. CAN line
Communication with GDS is not possible. (Communication with ABS only is not possible)	1. Power source circuit 2. CAN line 3. HECU
When ignition key is turned ON (engine OFF), the ABS warning lamp does not light up.	1. ABS warning lamp circuit 2. HECU
Even after the engine is started, the ABS warning lamp remains ON.	1. ABS warning lamp circuit 2. 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.

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 ABS 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.

3.	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 ABS control module.

2.	Turn the ignition switch ON, measure the voltage between terminal 29 of the ABS control module harness side connector and body ground. Specification: approximately B+

3.	Is the voltage within specification? ? Check the ground circuit. ? Check the harness or connector between the fuse (10A) in the engine compartment junction block and the ABS control module. Repair if necessary.

Check the ground circuit

1.	Disconnect the connector from the ABS control module.

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

3.	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.

2.	Is it normal? ? Check the hydraulic circuit for leakage. ? Repair or replace the wheel speed sensor.

Check the hydraulic circuit for leakage

1.	Refer to the hydraulic lines.

2.	Inspect leakage of the hydraulic lines.

3.	Is it normal? ? The problem is still occurring, replace the ABS control module. ? Repair the hydraulic lines for leakage.

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 ABS 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.

3.	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.

2.	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.

2.	Measure the voltage between terminal 23 of the ABS control module harness side connector and body ground when brake pedal is depressed. Specification : approximately B+

3.	Is the voltage within specification? ? Check the hydraulic circuit for leakage. ? Repair the stop lamp switch. Repair an open in the wire between the ABS 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.

3.	Is it normal? ? The problem is still occurring, replace the ABS 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

1.	Measure the voltage between terminal 16 of the data link connector and body ground. Specification : approximately B+

2.	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

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

2.	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 ABS control module.

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

3.	Is there continuity? ? Check the power source of ABS control module. ? Repair an open in the wire.

Check the power source of ABS control module

1.	Disconnect the connector from the ABS control module.

2.	Turn the ignition switch ON, measure the voltage between terminal 29 of the ABS control module harness side connector and body ground. Specification : approximately B+

3.	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 ABS control module.Repair if necessary.

Check for poor ground

1.	Check for continuity between terminal 4 of the data link connector and ground point. ? Replace the ABS 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 module - Faulty HECU

Inspection procedures

Problem verification

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

2.	Does the ABS warning lamp light up? ? Inspectagain after replacing the ABS 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.

2.	Measure the voltage between terminal (M08) 39 of the cluster harness side connector and body ground. Specification : approximately B+

3.	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.

2.	Measure the resistance between terminal (M08) 32 and 33 of the cluster harness side connector. Specification : 60?

3.	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 ABS HECU connector, and then turn the ignition switch OFF.

2.	Check for continuity between terminal (M08) 32 of the cluster harness side connector and terminal 26 of ABS HECU harness side. Check for continuity between terminal (M08) 33 of the cluster harness side connector and terminal 14 of ABS HECU harness side. Specification : Below 1?

3.	Is resistance within specification? ? Repair short of wiring between terminal 26, 14 of ABS HECU harness connector and ABS warning lamp module. ? Repair open of wiring between terminal 26, 14 of ABS 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.

3.	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.

2.	Measure the resistance between terminal (M08) 32 and 33 of the cluster harness side connector. Specification : 60?

3.	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 ABS HECU connector, and then turn the ignition switch OFF.

2.	Check for continuity between terminal (M08) 32 of the cluster harness side connector and terminal 26 of ABS HECU harness side. Check for continuity between terminal (M08) 33 of the cluster harness side connector and terminal 14 of ABS HECU harness side. Specification : Below 1?

3.	Is resistance within specification? ? Repair short of wiring between terminal 26, 14 of ABS HECU harness connector and ABS warning lamp module. ? Repair open of wiring between terminal 26, 14 of ABS HECU harness connector and ABS warning lamp module.

ABS Control Module 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. ABS control module(HECU) 8. Bracket

ABS Control Module 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)

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 ABS - "ABS System Bleeding")

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