If a normal code is displayed during the DTC check but the problem still occurs, check the circuits for each problem symptom in the order given in the table below and proceed to the relevant troubleshooting page.

PROBLEM SYMPTOMS CHART

Symptom	Suspect Area	See
ABS does not operate.	Only when 1. -4. are all normal and the problem is still occurring, replace the HECU. Check the DTC reconfirming that the normal code is output. Power source circuit. Speed sensor circuit. Check the hydraulic circuit for leakage.	ABS DOES NOT OPERATE.
ABS does not operate intermittently.	Only when 1. -4. are all normal and the problem is still occurring, replace the ABS actuator assembly. Check the DTC reconfirming that the normal code is output. Wheel speed sensor circuit. Stop lamp switch circuit. Check the hydraulic circuit for leakage.	ABS DOES NOT OPERATE (INTERMITTENTLY).
Communication with Scan tool is not possible. (Communication with any system is not possible)	Power source circuit Diagnosis line	COMMUNICATION WITH SCAN-TOOL IS NOT POSSIBLE.; (COMMUNICATION WITH ANY SYSTEM IS NOT POSSIBLE)
Communication with Scan tool is not possible. (Communication with ABS only is not possible)	Power source circuit Diagnosis line HECU	COMMUNICATION WITH SCAN TOOL IS NOT POSSIBLE.; (COMMUNICATION WITH ABS ONLY IS NOT POSSIBLE)
When ignition key is turned ON (engine OFF), the ABS warning lamp does not light up.	ABS warning lamp circuit HECU	WHEN IGNITION KEY IS TURNED ON (ENGINE OFF), THE ABS WARNING LAMP DOES NOT LIGHT UP.
Even after the engine is started, the ABS warning lamp remains ON.	ABS warning lamp circuit HECU	EVEN AFTER THE ENGINE IS STARTED, THE ABS WARNING LAMP REMAINS ON.

CAUTION: 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.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Problem Symptoms Table: Notes

Use the Manual With the Right Hardware

When to See a Mechanic

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