Hyundai Tucson: Electronic Stability Control  System- Components

1. ESC Control unit (HECU)
2. Front wheel speed sensor
3. Rear wheel speed sensor
4. ABS warning lamp
5. Parking brake / EBD

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 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. ESC warning lamp turn on for 3sec after IGN ON.
2. ESC function lamp blinks when ESC Act.
3. If ESC fail occured, ESC warning turns ON.
4. ESC OFF lamp turn on in case of

• ESC 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.

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.

1. 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 diagnostic tool.

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

(1) Self-diagnose using diagnostic tool.

(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.

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

WARNING

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

WARNING

• 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.

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