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Home >> Kia >> 2017 >> Optima Plug-In Hybrid EX >> Repair and Diagnosis >> Transmission >> Automatic Trans >> Automatic Transaxle System Diagnosis (PHEV) >> DTC P0721: Output Speed Sensor Circuit Range/Performance >> Component Inspection >> Notes
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Component Inspection: Notes

  1. Ignition "OFF"
  2. Refer to REPAIR PROCEDURES and LIFT AND SUPPORT POINTS and remove necessary parts to get access to ATM Solenoid connector and lift vehicle with suitable lift.
  3. Engine "ON"
  4. Back probe and measure signal waveform between Pin No. 4 (Signal) terminal of ATM Solenoid harness connector and chassis ground.

    Specification  : High - Approx. 1.5V/Low - Approx. 0.7V

    Fig 1: Input Speed & Output Speed Data And Signal Waveform At Engine "ON", Gear Lever Position At "P/N"
    G12348079Courtesy of KIA MOTORS AMERICA, INC.
    Fig 2: Input Speed & Output Speed Data And Signal Waveform At Engine "ON", Gear Lever Position At "R" And No Brake Pedal Applied
    G12348080Courtesy of KIA MOTORS AMERICA, INC.
    Fig 3: Input Speed & Output Speed Data And Signal Waveform At Engine "ON", Gear Lever Position At "D" And Vehicle Speed At Approx. 30 KM/H (18.6MPH)
    G12348081Courtesy of KIA MOTORS AMERICA, INC.
  5. Is the measured value within specification?

    YES 

    NO 

    • Carefully re-do this troubleshooting guide steps.
    • If problem still occurs, replace Output Speed Sensor and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.