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Home >> Kia >> 2017 >> Rio SX >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Idle Stop And Go (ISG) System >> Description And Operation >> Operation Condition For The ISG function
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Operation Condition For The ISG function

  1. (Auto stop or Auto start condition (If all of the below condition are satisfied) 
    Items State Remark
    Driving conditions ISG OFF Switch Off  
    Switch (seat/door/hood) Closed  
    Lever position D or N range Prohibit operation on gear 'P, R'
    Brake pedal Pressed Auto Stop
    Released Auto Start
    Vehicle speed Vehicle speed = 0 Mph After driving higher than 8 kph (5 Mph)
    Engine Coolant Temperature (ECT) Over 78 °C (172.4 °F)  
    Brake Pressure Below -35 kpa  
    Battery conditions SOC Over 77% To protect Battery
    Temperature 2 ~ 55 °C (35.6 ~ 131 °F)  
    Steering wheel Operating angle Below 180°  
    Parking condition Slope Up hill <12%, Down hill < 8%  
    ISG related part error Sensor Error Brake Booster Pressure Sensor
    Brake Master Cylinder Pressure
    Sensor, Brake Pedal Sensor,
    APS, Battery Sensor
    Related System Error TM Electronic Auxiliary Pump
    ESC System Defect Mode
    CAN Communication Error
    Engine Limp Home Mode
  2. (Forced re-start conditions (If any of the below condition is not satisfied) 
    Component Conditions State Remark
    Conditions for safety Low pressure for braking system Over -35 kpa  
    Low battery voltage Below 12.1V for 180 sec  
    Active defroster of front glass On  
    When inertial speed reach 1Mph with (down hill) Over 1Mph (Kph) Inertial Speed
    Open the door or unfasten driver's seat belt Open Brake Pedal Pressed
    Elapsed much of stop time
    On the steep slope way
    Conditions for convenience Turn on the air-conditioner or max blower speed or bad performance of air conditioning and heating
    Active 'ISG OFF' button
    Sign of forced auto re-start Blinking of lamp for 5 second and indicating on cluster
  3. Restriction conditions for Auto-Stop operation 

    * To protect system and safety auto-stop system is restricted below the conditions

    Large steering angle when car is stop
    Low brake operating pressure
    Turn on the air conditioner with max blower
    When battery Condition is poor (low SOC)
    Active defroster of front or rear glass
    Unfasten driver's seat belt or open the door and hood
    On the steep slope way
    With ISG system errors, and other diagnosis
  4. Restriction condition for auto Re-Start operation 

    Open hood (have to restart by key for repairman's safety)

  5. Restriction Condition for OBD Check & Emission Control 
    Auto Stop system will be limited During Canister purge monitoring
    During OBD check
    To restrict continuous Cranking (for Emission Control) Start Motor can operate for two seconds at the longest (just once)
    CAUTION: The ISG system is strongly networked with the power management. In the event of battery replacement, disconnection of the battery terminal or after changing the engine management system, the reference (Ω) data regarding the battery charge state and battery condition can be lost.
    They are only available again a closed-circuit current measurement of approximate 4 hours in which the vehicle may not be wakened. In this time, the ISG system is inactive.
    CAUTION: ISG system deactivation by fault.
    • Fault in communication line (LIN/CAN)

      Fault Electric oil pump

      Fault ESC System

      Fault Limp home mode

    • Fault brake booster vacuum pressure sensor

      Fault Brake master cylinder pressure sensor

      Fault Brake pedal switch

      Fault Battery sensor


    When the ISG related sensors or system error occurs, the ISG OFF switch lights up. Especially when the battery sensor is replaced or reinstalled, the vehicle must be placed in the ignition switch OFF for about 4 hours for recalibration.
    The ISG function is operated about 4 hours later normally. But in the case of first 25 times, the ISG function can be operated regardless of recalibration.
    WARNING: When the engine is in Idle stop mode, it's possible to restart the engine without the driver taking any action.
    Before leaving the car or doing anything in the engine room area, stop the engine by turning the ignition key to the LOCK position or removing it.