Hyundai Tucson: ABS Does Not Operate/ ABS Does Not Operate (Intermittently)

ABS Does Not Operate

Detecting condition

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 ESC 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 diagnostic tool 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 diagnostic tool.

Check the power source circuit

1. Disconnect the connector from the ESC control module.
2. Turn the ignition switch ON, measure the voltage between terminal 29 of the ESC control module harness side connector and body ground.

Specification : approximately B -

Is the voltage within specification?

  Check the ground circuit.

Check the harness or connector between the fuse (7.5A) in the engine compartment junction block and the ESC control module. Repair if necessary.

Check the ground circuit

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

   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. Inspect leakage of the hydraulic lines.
2. Is it normal?

The problem is still occurring, replace the ESC control module.

Repair the hydraulic lines for leakage.

ABS Does Not Operate (Intermittently).

Detecting condition

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 ESC 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 diagnostic tool 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 diagnostic tool.

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 ESC control module harness side connector and body ground when brake pedal is depressed.

Specification : approximately B +

Is the voltage within specification?

Check the hydraulic circuit for leakage.

Repair the stop lamp switch. Repair an open in the wire between the ESC 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 ESC control module.

Repair the hydraulic lines for leakage.

Communication with KDS is not possible.

(Communication with any system is not possible)

Detecting condition

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 +

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.

   Is there continuity?

Repair an open in the wire between terminal 4 of the data link connector and ground point.

Communication with KDS is not possible.

(Communication with ABS only is not possible)

Detecting condition

When communication with diagnostic tool 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 ESC control module.
2. Check for continuity between terminals 26, 14 of the ESC control module connector and 3, 11 of the data link connector.
3. Is there continuity?

Check the power source of ESC control module.

Repair an open in the wire.

Check the power source of ESC control module

1. Disconnect the connector from the ESC control module.
2. Turn the ignition switch ON, measure the voltage between terminal 29 of the ESC control module harness side connector and body ground.

Specification : approximately B+

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 ESC control module.Repair it necessary.

Check for poor ground

1. Check for continuity between terminal 4 of the data link connector and ground point.
2. Is the electric current applied between groundings?

Replace the ESC control module and recheck.

Repair an open in the wire or poor ground

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