2011 Hyundai Equus SignatureFACTORY OEM SERVICE PROCEDURE

Problem Symptoms Table

If a normal code is displayed during the DTC check that 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 REFERENCE CHART

Symptom Suspect Area Remarks
ABS does not operate. Only when 1. ~ 4. are all normal and the problem is still occurring, replace the HECU.
  1. Check the DTC reconfirming that the normal code is output.
  2. Power source circuit.
  3. Speed sensor circuit.
  4. Check the hydraulic circuit for leakage.
  
ABS does not operate intermittently. Only when 1. ~ 4. are all normal and the problem is still occurring, replace the ABS actuator assembly.
  1. Check the DTC reconfirming that the normal code is output.
  2. Wheel speed sensor circuit.
  3. Stop lamp switch circuit.
  4. Check the hydraulic circuit for leakage.
  
Communication with GDS
is not possible.
(Communication with any system is
not possible)
  1. Power source circuit
  2. Diagnosis line
  
Communication with GDS
is not possible.
(Communication with ABS only is
not possible)
  1. Power source circuit
  2. Diagnosis line
  3. HECU
  
When ignition key is turned ON
(engine OFF),
the ABS warning lamp does not light up.
  1. ABS warning lamp circuit
  2. HECU
  
Even after the engine is started, the ABS
warning lamp remains ON.
  1. ABS warning lamp circuit
  2. HECU
  
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.
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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.

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