Diagnostic System Check - Brake Controls (ABS/ESC)

1. Warning light illumination check

1) Turn ON the ignition switch.

2) Check the ABS, ESC, and brake system warning lights. Does the warning light turn OFF after illuminating?

Yes

=>Go to Scan tool power-up check.

No

Go to ABS warning light illuminating circuit system check.

Refer to "54.Brake Control 4A.Troubleshooting(ABS/ESC) ABS warning light illuminating circuit system check".

2. Scan tool power-up check

1) Connect the scan tool.

2) Check whether the scan tool powers up. Does the scan tool power up?

Yes (Models with radar sensors/stereo cameras)

=>Go to Central gateway control unit communication verification.

Yes (Models without radar sensors and stereo cameras)

=>Go to EHCU communication verification.

No

Go to Scan tool does not power up.

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 with DPD) Scan tool does not power up".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) Scan tool does not power up".

Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) Scan tool does not power up".

3. Central gateway control unit communication verification

1) Verify communication with the central gateway control unit using the scan tool. Can communication with the central gateway control unit be established?

Yes

=>Go to EHCU communication verification.

No

Go to Lost communication with the central gateway control unit.

Refer to "64.Body Control 10I.Troubleshooting(Central GateWay) lost communication with the central gateway control unit".

=>Go to EHCU communication verification.

4. EHCU communication verification

1) Verify communication with the EHCU using the scan tool. Can communication with the EHCU be established?

Yes

=>Go to Current DTC check.

No (Models with radar sensors/stereo cameras)

Go to Lost communication with the EHCU.

Refer to "54.Brake Control 4A.Troubleshooting(ABS/ESC) lost communication with the EHCU (models with radar sensor/ stereo camera)".

No (Models without radar sensors and stereo cameras)

Go to Lost communication with the EHCU.

Refer to "54.Brake Control 4A.Troubleshooting(ABS/ESC) lost communication with the EHCU (models without radar sensor and stereo camera)".

5. Current DTC check

1) Observe the DTC information with a scan tool. Is a DTC set?

Yes

Go to the applicable DTC diagnosis.

No

=>Go to Symptom check.

6. Symptom check

1) Check if the following symptoms are present. Is there any applicable symptom?

Yes

Refer to "205.Brakes 18D.Symptom ABS works frequently but the brake is not effective or TCS operates frequently".

Refer to "205.Brakes 18D.Symptom uneven braking occurs while ABS works".

Refer to "205.Brakes 18D.Symptom wheels lock when braking".

Refer to "205.Brakes 18D.Symptom brake pedal feeling is abnormal".

Refer to "205.Brakes 18D.Symptom brake operation sounds are heard from the hydraulic unit even though the brake is not applied".

Refer to "205.Brakes 18D.Symptom ESC does not work efficiently".

No

The system is normal.