2011 Hyundai Equus SignatureFACTORY OEM SERVICE PROCEDURE

Component Inspection

  • Check the Signal waveform of HO2S 
    1. IG "OFF" and connect HO2S connector.
    2. Engine start.
    3. After warming-up, monitor signal waveform of HO2S with GDS.

      Specification:  Refer to SIGNAL WAVEFORM & DATA 

      Fig 1: Measuring Signal Waveform Between Oxygen Sensor And ECM
      G07305801Courtesy of HYUNDAI MOTOR CO.
    4. Is the sensor switching properly?

      YES 

      • Go to "Check HO2S  " as below.

      NO 

      • Substitute with a known - good HO2S and check for proper operation. If the problem is corrected, go to "VERIFICATION OF VEHICLE REPAIR " procedure.
  • Check HO2S 
    1. IG "OFF" and disconnect HO2S connector.
    2. Check that the HO2S is securely installed.
    3. Check the HO2S for contamination or damage.
    4. Is the sensor normal?

      YES 

      • Substitute with a known - good ECM and check for proper operation. If the problem is corrected, replace ECM and go to "VERIFICATION OF VEHICLE REPAIR " procedure.

      NO 

      • Substitute with a known - good HO2S and check for proper operation. If the problem is corrected, go to "VERIFICATION OF VEHICLE REPAIR " procedure.
Factory Service Tools

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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.