Hyundai Kona Quiz
Brake System

Troubleshooting

In this manual: Brake System
General Information — 17Engine Mechanical System — 85Engine Electrical System — 50Emission Control System — 26Engine Control System/Fuel System — 152DCT (Dual Clutch Transmission) System — 50Four-Wheel Drive (4WD) System — 21Propeller Shaft and Axle (2WD-FF) — 28Suspension System (without ECS) — 32Steering — 21Restraints — 38Brake System — 64Body (Interior and Exterior) — 205Body Electrical System — 1Heating, Ventilation, and Air Conditioning — 66
94steps
~564min
5/5difficulty
Done 0 of 94

Fault Diagnosis

  1. In principle, ESP and TCS control is prohibited when an ABS failure occurs.
  2. If an ESP or TCS failure occurs, only the malfunctioning system control is prohibited.
  3. However, when the solenoid valve relay must be turned off in the event of an ESP failure, refer to ABS fail-safe.
  4. ABS fail-safe information is identical to the fail-safe for systems where ESP is not installed.
  5. It stores the code as long as backup lamp power is connected. (O)
  6. It stores the code as long as HCU power is on. (X)
  7. The initial check is performed immediately after the HECU is powered on.
  8. The valve relay check is performed immediately after IG2 is turned on.
  9. It performs the check at all times while IG2 power is on.
  10. The initial check is performed in the following cases.
    1. When no fault is detected.
    2. When ABS and ESP are not monitored.
    3. The initial check is not performed after the ECU is powered on.
    4. If vehicle speed exceeds 8 km/h when the stop lamp switch is OFF.
    5. When the vehicle speed exceeds 24.8 mph (40 km/h).
  11. However, the check continues even when the stop lamp switch is on.
  12. When performing ABS or ESP control before the initial check, stop the initial check and wait again for HECU power input.
  13. The judgment fails in the following cases.
    1. When the power supply is normal.
    2. From the moment the vehicle speed reaches 4.9 mph (8 km/h) after the HECU is turned on.
  14. Turn the system off, perform the following steps, and wait until the HECU is turned off.
  15. Turn off the valve relay.
  16. Do not perform any ABS/TCS/ESP functions until normal operating condition is restored.
  17. The ABS warning lamp illuminates when an ABS malfunction occurs.
  18. The ESP function/warning lamp illuminates when an ESP malfunction occurs.
Trouble Code Memory, Fault Check, Countermeasures in Case of Failure, Warning Lamp ON: When the power supply voltage and the valve relay voltage are not normal, the input/output related to the failure is not judged. Standard Diagnostic Flow for Troubleshooting. Notes on Diagnosis: The phenomena listed in the following table are not abnormal.
Condition Description
System Check Sound When the engine is started, a dull knocking sound may sometimes be heard
from the engine compartment. This is because the system
performs a self-check.
ABS Operation Sound
  1. A motor sound (whining) can be heard inside the ABS hydraulic unit.
  2. A grinding sound is generated together with brake pedal vibration.
  3. When the ABS is operating, the noise comes from the vehicle chassis due to repeated depressing and releasing of the brake pedal. (Knocking: suspension; squeaking: tires)
ABS Operation (Longer Stopping Distance) On road surfaces such as snow-covered and gravel roads, the braking distance of vehicles equipped with ABS may sometimes be longer than that of other vehicles. Therefore, advise the customer to drive safely on such roads by reducing vehicle speed.

Diagnostic detection conditions may differ depending on the diagnostic trouble code. When checking for symptoms of a malfunction after the diagnostic trouble code has been erased, make sure the requirements listed in "Comments" are met. ABS Checklist
Symptom Table
Symptom Suspect area
ABS does not operate. Only when items 1-4 are normal and the problem still occurs, replace the HECU.
  1. Check the DTC to confirm that a normal code is output.
  2. Power supply circuit.
  3. Speed sensor circuit.
  4. Check the hydraulic circuit for leaks.
ABS does not operate intermittently. Only when items 1-4 are normal and the problem still occurs, replace the ABS actuator assembly.
  1. Check the DTC to confirm that a normal code is output.
  2. Wheel speed sensor circuit.
  3. Stop lamp switch circuit.
  4. Check the hydraulic circuit for leaks.
Communication with GDS
is not possible.
(Communication with any system
is not possible)
  1. Power supply circuit
  2. CAN line
Communication with GDS
is not possible.
(Communication with ABS only
is not possible)
  1. Power supply circuit
  2. CAN line
  3. HECU
When the ignition switch is ON
(engine off),
the ABS warning lamp does not illuminate.
  1. ABS warning lamp circuit
  2. HECU
Even after starting the engine, the ABS
warning lamp remains illuminated.
  1. ABS warning lamp circuit
  2. HECU

Detection condition
Symptom Condition Possible Cause
Brake operation depends on driving conditions and road surface conditions, so diagnosis may be difficult. However, if a normal trouble code is displayed, check the following possible causes. If the problem still occurs, replace the ABS control unit.
  • Faulty power supply circuit
  • Faulty wheel speed sensor circuit
  • Faulty hydraulic circuit due to leakage
  • Faulty HECU

Inspection Procedures. Check DTC.
  1. Connect the GDS to the data link connector and turn the ignition switch ON.
  2. Make sure that a DTC is output.
  3. Is a DTC output?
    		 ▶ Check the power supply circuit.
    		▶ Clear the trouble code and recheck using the GDS.
  4. Disconnect the 38-pin connector from the ABS HECU control module.
  5. Turn the ignition ON, then measure the voltage between terminal 6 of the ABS control module harness side connector and body ground.

    Specification: Approximately B+

  6. 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.
  7. Disconnect the connector from the ABS control module.
  8. Check the continuity of the circuit between terminals 13 and 38 of the ABS control module harness side connector and the ground point.
  9. Is there continuity?
  		10.  ▶ Check the wheel speed sensor circuit.
    		▶ Repair the open in the wire and the ground point.
  11. Refer to DTC troubleshooting procedures.
  12. Is this normal?
    		 ▶ Check the hydraulic circuit for leakage.
    		▶ Repair or replace the wheel speed sensor.
  13. Check the hydraulic lines for leaks.
  14. Is this normal?
    		 ▶ If the problem remains, replace the ABS control module.
    		▶ Repair the hydraulic line for leakage.
Check the power supply circuit. Check the ground circuit. Check the wheel speed sensor circuit. Check the hydraulic circuit for leaks. Detection condition
Symptom Condition Possible Cause
Brake operation depends on driving conditions and road surface conditions, so diagnosis may be difficult. However, if a normal trouble code is displayed, check the following possible causes. If the problem still occurs, replace the ABS control unit.
  • Faulty wheel speed sensor circuit
  • Faulty hydraulic circuit due to leakage
  • Faulty HECU

Inspection Procedures. Check DTC.
  1. Connect the GDS to the data link connector and turn the ignition switch ON.
  2. Make sure that a DTC is output.
  3. Is a DTC output?
    		 ▶ Check the wheel speed sensor circuit.
    		▶ Clear the trouble code and recheck using the GDS.
  4. Inspect the wheel speed sensor and circuit. (Refer to "DTC Troubleshooting Procedures").
  5. Is this normal?
    		 ▶ Check the stop lamp switch circuit.
    		▶ Repair or replace the wheel speed sensor.
  6. Verify that the stop lamp illuminates when the brake pedal is depressed and goes off when the brake pedal is released.
  7. Measure the voltage between terminal 23 of the ABS control module harness side connector and body ground while the brake pedal is depressed.

    Specification: Approximately B+

  8. Is the voltage within specification?
    		 ▶ Check the hydraulic circuit for leakage.
    		▶ Repair the stop lamp switch. Repair the open in the wire between the ABS control module and the stop lamp switch.
  9. Refer to hydraulic lines.
  10. Check the hydraulic lines for leaks.
  11. Is this normal?
    		 ▶ If the problem remains, replace the ABS control module.
    		▶ Repair the hydraulic line for leakage.
Check the wheel speed sensor circuit. Check the stop lamp switch circuit. Check the hydraulic circuit for leaks. Detection condition
Symptom Condition Possible Cause
A possible malfunction exists in the power supply (including ground) circuit for the diagnostic line.
  • Open in the wire
  • Poor ground
  • Faulty power supply circuit

Inspection Procedures. Check the power supply circuit for diagnosis.
  1. Measure the voltage between terminal 16 of the data link connector and body ground.

    Specification: Approximately B+

  2. Is the voltage within specification?
    		 ▶ Check the ground circuit for diagnosis.
    		▶ Repair the open in the wire. Check and replace the fuse from the engine compartment junction block.
  3. Check the continuity of the circuit between terminal 4 of the data link connector and body ground.
  4. Is there continuity?
    		 ▶ Repair the open in the wire between terminal 4 of the data link connector and the body ground point.
Check the ground circuit for diagnosis. Detection condition
Symptom Condition Possible Cause
If communication with the GDS is not possible, the cause may be an open in the HECU power supply circuit or an open in the diagnostic output circuit.
  • Open in the wire
  • Faulty HECU
  • Faulty power supply circuit

Inspection Procedures. Check the CAN line integrity.
  1. Disconnect the connector from the ABS control module.
  2. Check the continuity of the circuits between terminals 26, 14 of the ABS control module connector and terminals 3, 11 of the data link connector.
  3. Is there continuity?
    		 ▶ Check the power supply to the ABS control module.
    		▶ Repair the open in the wire.
  4. Disconnect the connector from the ABS control module.
  5. Turn the ignition ON, then measure the voltage between terminal 29 of the ABS control module harness side connector and body ground.

    Specification: Approximately B+

  6. Is the voltage within specification?
    		 ▶ Check for a poor ground connection.
    		▶ Check the harness or connector between the fuse (10A) in the engine compartment junction block and the ABS control module. Repair if necessary.
  7. Check the continuity of the circuit between terminal 4 of the data link connector and the ground point.
    		 ▶ Replace the ABS control module and recheck.
    		▶ Repair the open in the wire or the poor ground connection.

Check the power supply to the ABS control module. Check for poor grounding. Detection condition
Symptom Condition Possible Cause
When current flows through the HECU, the ABS warning lamp turns off.
Turn the ignition switch to OFF for the initial check. Therefore, if the lamp does not illuminate,
the cause may be an open in the lamp power supply circuit, a burned-out bulb,
an open in both circuits between the ABS warning lamp and the
HECU, or a faulty HECU.
  • Faulty ABS warning lamp bulb
  • The blown fuse is related to the ABS in the engine compartment junction block.
  • Faulty ABS warning lamp module
  • Faulty HECU

Inspection Procedures. Check the problem.
  1. Disconnect the connector from the ABS control module and turn the ignition ON.
  2. Does the ABS warning lamp illuminate?
    		 ▶ Recheck after replacing the ABS HECU.
    		▶ Check the power supply to the ABS warning lamp.
  3. Disconnect the instrument cluster connector (M08) and turn the ignition ON.
  4. Measure the voltage between terminal (M08) 39 of the instrument cluster harness side connector and body ground.

    Specification: Approximately B+

  5. Is the voltage within specification?
    		 ▶ Check the CAN circuit and the resistance of the ABS warning lamp.
    		▶ Check whether the fuse is blown.
  6. Disconnect the instrument cluster connector (M08) and turn the ignition OFF.
  7. Measure the resistance between terminals (M08) 32 and 33 of the instrument cluster harness side connector.

    Specification: 60 Ω

  8. Is the resistance within specification?
    		 ▶ Repair the ABS warning lamp or replace the instrument cluster assembly.
    		▶ Check the CAN electrical circuit of the ABS warning lamp.
  9. Disconnect the instrument cluster connector (M08) and the ABS HECU connector, then turn the ignition OFF.
  10. Check the continuity of the circuit between terminal (M08) 32 of the instrument cluster harness side connector and terminal 26 of the ABS HECU harness side connector. Check the continuity of the circuit between terminal (M08) 33 of the instrument cluster harness side connector and terminal 14 of the ABS HECU harness side connector.

    Specification: Less than 1 ohm

  11. Is the resistance within specification?
    		 ▶ Repair the short circuit in the wiring between terminals 26, 14 of the ABS HECU harness connector and the ABS warning lamp module.
    		▶ Repair the open circuit in the wiring between terminals 26, 14 of the ABS HECU harness connector and the ABS warning lamp module.
Check the power supply to the ABS warning lamp. Check the resistance of the ABS warning lamp CAN circuit. Check the wiring of the ABS warning lamp CAN circuit. Detection condition
Symptom Condition Possible Cause
If the HECU detects a malfunction, it turns on the ABS warning lamp and
simultaneously disables ABS control. At this time, the HECU stores the
DTC in memory. Even though a normal code is output, if the ABS
warning lamp remains on, the cause may be an open or short circuit
in the ABS warning lamp circuit.
  • Open in the wire
  • Faulty instrument cluster assembly
  • Faulty ABS warning lamp module
  • Faulty HECU

Inspection Procedures. Check the DTC output.
  1. Connect the GDS to the 16-pin data link connector located behind the driver's side kick panel.
  2. Check the DTC output using the GDS.
  3. Is a DTC output?
    		 ▶ Perform the DTC troubleshooting procedure (refer to DTC troubleshooting).
    		▶ Check the CAN circuit and the resistance of the ABS warning lamp.
  4. Disconnect the instrument cluster connector (M08) and turn the ignition OFF.
  5. Measure the resistance between terminals (M08) 32 and 33 of the instrument cluster harness side connector.

    Specification: 60 Ω

  6. Is the resistance within specification?
    		 ▶ Repair the ABS warning lamp or replace the instrument cluster assembly.
    		▶ Check the CAN circuit and the ABS warning lamp wiring.

  7. Disconnect the instrument cluster connector (M08) and the ABS HECU connector, then turn the ignition OFF.
  8. Check the continuity of the circuit between terminal (M08) 32 of the instrument cluster harness side connector and terminal 26 of the ABS HECU harness side connector. Check the continuity of the circuit between terminal (M08) 33 of the instrument cluster harness side connector and terminal 14 of the ABS HECU harness side connector.

    Specification: Less than 1 ohm

  9. Is the resistance within specification?
    		 ▶ Repair the short circuit in the wiring between terminals 26, 14 of the ABS HECU harness connector and the ABS warning lamp module.
    		▶ Repair the open circuit in the wiring between terminals 26, 14 of the ABS HECU harness connector and the ABS warning lamp module.
Check the resistance of the ABS warning lamp CAN circuit. Check the CAN circuit wiring for the ABS warning lamp.

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