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Home >> Hyundai >> 2005 >> Elantra GLS, 4D Hatchback, Standard >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Fuel System >> DTC Troubleshooting Procedures >> DTC P2251: Ho2S Reference Ground Circuit/Open-Bank 1, Sensor 1 >> Component Inspection
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Component Inspection

  1. Visually/physically inspect following items:
    • Visually/physically inspect the front HO2S for contamination, deterioration, or damage.
    • Inspect the front HO2S for any silicon contamination. This contamination will be indicated by a white powdery coating and this will result in a but false voltage signal
    • If contamination is evident on the HO2S, replace contaminated sensor and go to next step.
  2. Warm up the engine to normal operating temperature and check that HO2S signal is active.
  3. Connect Scantool and monitor the "O2 SNSR VOLT.(B1/S1)" parameter on the Scantool data list.

    Test Condition : Engine "ON" & In Closed loop mode

    Fig 1: Scantool Parameter Data List
    G03842976Courtesy of HYUNDAI MOTOR CO.
  4. Is sensor data near the specified value?

    YES 

    • Check for poor connection between PCM and component: backed out terminal, improper mating, broken locks or poor terminal to wire connection. Repair as necessary and go to VERIFICATION OF VEHICLE REPAIR  procedure

    NO 

    • Check HO2S for contamination, deterioration, or damage. Substitute with a known-good HO2S and check for proper operation. If the problem is corrected, replace HO2S and then go to VERIFICATION OF VEHICLE REPAIR  procedure.