FixVault

O2 Sensor Signal Inspection

  1. Ignition "OFF".
  2. Connect VMI to GDS and set up an oscilloscope as follow (4-channel);

    Channel A (+) : Pin No. 3 (V_IP) terminal of Upstream O2 Sensor.

    Channel A (-) : Ground

    Channel B (+) : Pin No. 1 (Signal) terminal of Downstream O2 Sensor.

    Channel B (-) : Ground

  3. Ignition "ON" & Engine "ON".
    Fig 1: Upstream & Downstream O2 Sensor Signal Waveform - Warm-Up Condition
    G00552068Courtesy of KIA MOTORS AMERICA, INC.

    A : Approx. 2500 RPM.

    B : Fuel Cut after acceleration.

  4. Is measured value within specification?

    YES 

    • Go to next procedure.

    NO 

    • Carefully re-do this troubleshooting guide steps.
    • If no problems were found with the circuits or connectors, Replace the O2 Sensor and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.
    CAUTION:
    • Install the component with the specified torques.
    • Note that internal damage may occur when the component is dropped or mis- treated.
    CAUTION:
    • DO NOT use a cleaner, spray, or grease to sensing element and connector of the sensor because oil component in them may cause malfunction or affects on sensor performance.
    • Sensor and its wiring may be damaged in case of contacting with the exhaust system (Exhaust Manifold, Catalytic Converter, and others).