Troubleshooting
1.The brake system can be diagnosed quickly using the KDS (Refer to "DTC Diagnostic Guide").
(1)Self diagnosis : Checking failure and code number (DTC)
(2)Sensor data : Checking the system input/output data state
(3)Forced operation : Checking the system operation condition
(4)Additional function : Controlling other features including system option setting and zero point adjustment
The table below shows the most common defects and repair remedies in the brake system. Each number indicates the priority of the likely cause of the defects.Brake warning lamp illuminates
| Suspected Cause | Correction |
| 1. Brake fluid level sensor (not connected securely) | Reconnect or replace |
| 2. Low brake fluid level | Fill and leak check |
| 3. Parking brake (Set) | Release |
| 4. Integrated Electronic Brake (IEB) | Diagnosis Trouble Code (DTC) Inspection |
Lower pedal or spongy pedal
| Suspected Cause | Correction |
| 1. Brake system (fluid leakage) | Repair |
| 2. Brake system (air inflow) | Perform air bleeding procedure |
| 3. Piston seal (Wear or damage) | Replacement |
| 4. Integrated Electronic Brake (IEB) | Diagnosis Trouble Code (DTC) Inspection |
Brake drag
| Suspected Cause | Correction |
| 1. Brake pedal free separation (minimum) | Adjustment |
| 2. Pad (Crack or bent) | Replacement |
| 3. Piston (stuck) | Replacement |
| 4. Piston (frozen) | Replacement |
| 5. Anchor or return spring (malfunction) | Replacement |
| 6. Integrated Electronic Brake (IEB) | Diagnosis Trouble Code (DTC) Inspection |
Uneven brake
| Suspected Cause | Correction |
| 1. Piston (stuck) | Replacement |
| 2. Pad (Polluted) | Replacement |
| 3. Piston (frozen) | Replacement |
| 4. Disc (scratches) | Replacement |
| 5. Pad (Crack or bent) | Replacement |
Heavy pedal and brake trouble
| Suspected Cause | Correction |
| 1. Brake system (oil leakage) | Repair |
| 2. Brake system (air inflow) | Perform air bleeding procedure |
| 3. Pad (wear) | Replacement |
| 4. Pad (Crack or bent) | Replacement |
| 5. Pad (Polluted) | Replacement |
| 6. Pad (Slippery) | Replacement |
| 7. Disc (Dent or scratch) | Replacement |
| 8. Integrated Electronic Brake (IEB) | Diagnosis Trouble Code (DTC) Inspection |
Brake Noise
| Suspected Cause | Correction |
| 1. Pad (Crack or bent) | Replacement |
| 2. Mounting bolt (Loose) | Retighten |
| 3. Disc (Dent or scratch) | Replacement |
| 4. Sliding pin (Wear) | Replacement |
| 5. Pad (Polluted) | Cleaning |
| 6. Pad (Slippery) | Replacement |
| 7. Anchor or Return spring (Faulty) | Replacement |
| 8. Brake pad shim (Damaged) | Replacement |
Poor Braking Performance (at High Speed)
| Suspected Cause | Correction |
| 1. Pad (Wear) | Replacement |
| 2. Integrated Electronic Brake (IEB) | Diagnosis Trouble Code (DTC) Inspection |
Abnormal vibration when braking.
| Suspected Cause | Correction |
| 1. Excessive free play of the brake pedal | Adjustment |
| 2. Integrated Electronic Brake (IEB) | Diagnosis Trouble Code (DTC) Inspection |
| 3. Brake caliper | Replacement |
| 4. Master cylinder cap seal | Replacement |
| 5. Damaged brake line | Replacement |
| 6. Disc juddering | Perform brake judder inspection and resurface or replace the disc |
