Jump problem help

i ve problem with jump - jumpaction - checkischaracteronair numerators and methods so when my player falling down the first y position diffrent with current position after falling i cant understand why i cant falling first position exapmle my _characterGround value is 10.08, after falling current position is 10.07 or 10.06 is it a bug or my wrong ??? ty for help

 using System;
 using UnityEngine;
 using System.Collections;
 using System.Collections.Generic;

 sealed class CharacterBehaviour : Character, IMove 
 {
     
     #region Player's Status
     //This enum define _player's status
     private enum Status
     {
         Move, Jump, Wait, Run, ChangePosition    
     }
     #endregion
     
     #region Player's Land Status
     //This enum define _player's status
     private enum LandStatus
     {
         OnCenter, OnRight, OnLeft, OnMove    
     }
     #endregion
     
     #region Wanted Direction
     //This enum define user's wanted direction
     private enum Directions
     {
         Left, Right    
     }
     #endregion
     
     #region Public Variables
     public int myPlayerSpeed;
     public Transform playersLeft;
     public Transform playersRight;
     public Transform playersCenter;
     public float speedFactor;
     public GameObject player;
     public float transitionDuration;
     public const string playersName = "Player";
     public static int a = 5;
     public bool canPlayerGo;
     public List<BonusInfo> bonusList; //Storage bonus infos
     public bool canJump;
     public float jumpSpeed;
     public float maxJumpMeter;
     #endregion
     
     #region Private Variables
     private bool _isMove;
     private float _gameStartedTime;
     private bool _isDamage;
     private bool _canMove;
     private float _distance;
     private float _moveSpeed;
     private Transform _targetDirectionTransform;
     private GameObject _player;
     private Transform _playersTransform;
     private Transform _endPointTransform;
     private Transform _startPointTransform;
     private int _playerStatus;
     private int _playersLand;
     private Vector3 _playersPosition;
     private bool _canChangePosition;
     private const int _nullValue = -1;
     private bool _isPressedButton;
     private bool _isHit;
     private float _startPositionValue;
     private float _playerDistance; //Player's distance
     private int _totalScore;
     private bool _onAir;
     **private float _characterGroundPosition;**
     private const float _approachDistance = 5.0f;
     private const float _changeDirectionSpeed = 2.0f;
     private const float _approachDistanceForCenter = 0.4f;
     #endregion    
     
     protected override void Awake()
     {
         base.Awake();
         //Variables Values
         bonusList = new List<BonusInfo>();
         GameManager.isGameEnded = false;
         this.gameObject.transform.name = playersName;
         GameManager.playersName = playersName;
         _isHit = false;
         _canChangePosition = false;
         _isPressedButton = false;
         _player = this.gameObject;
         _playersTransform = _player.transform;
         _playersPosition = _playersTransform.position;
         _startPointTransform = _playersTransform;
         _endPointTransform = GameObject.FindWithTag("End Point").transform;
         _canMove = false;
         _onAir = false;
         _playerStatus = (int)Status.Wait;
         Debug.Log("This is ChatacterBehaviour's Awake Method");        
     }
     
     // Use this for initialization
     void Start () 
     {
         _gameStartedTime = Time.time;
         _startPositionValue = player.transform.position.z;
         _characterGroundPosition = player.transform.localPosition.y;
         **StartCoroutine("CheckValues");**
         
         if(canPlayerGo)
         {            
             StartCoroutine("Move");
         }
         
         Debug.Log("My Player's Speed = " + myPlayerSpeed);
     }
     
     // Update is called once per frame
     void Update () 
     {
 
     }
     
     #region ChackValues
     //This numerator to do check for is user pressed any key, distance of transforms and speed calculate
     public IEnumerator CheckValues()
     {
         while (true) 
         {
             _distance = Vector3.Distance(_startPointTransform.position, _endPointTransform.position);
             //10 meter per second
             _moveSpeed = Time.deltaTime * speedFactor;
             _playersTransform = _player.transform;
             CheckIsCharacterOnAir();
             //Check Is user click to Left or Right
             CheckUpControls();
             yield return null;
         }
     }
     #endregion
     
     #region
     //This method to do check is player on air?
     **private void CheckIsCharacterOnAir()**
     {
         if(player.transform.position.y == _characterGroundPosition)
         {
             _onAir = false;
             _playerStatus = (int)Status.Move;
         }
         
         else
         {
             _onAir = true;
             _playerStatus = (int)Status.Jump;
         }
     }
     #endregion
         
     #region Chack Up Controls
     //This method to do input's action
     private void CheckUpControls()
     {
         if(_canMove)
         {
             if(Input.GetKeyDown(KeyCode.Space) && canJump)
             {
                 _canChangePosition = false;
                 StartCoroutine("Jump");
             }
             
             if (Input.GetKeyDown(KeyCode.A) && !_onAir) 
             {
                 _isPressedButton = true;
                 _canChangePosition = true;
                 _targetDirectionTransform = playersLeft;
                 _playersLand = FindPlayersLand();
                 Debug.Log("Player's position number is :" + _playersLand);
                 ChoosePosition(_playersLand, (int)Directions.Left);
                 Debug.Log("User click LEFT");
             }
             
             else if (Input.GetKeyDown(KeyCode.D) && !_onAir) 
             {
                 _isPressedButton = true;
                 _canChangePosition = true;
                 _targetDirectionTransform = playersRight;
                 _playersLand = FindPlayersLand();
                 Debug.Log("Player's position number is :" + _playersLand);
                 ChoosePosition(_playersLand, (int)Directions.Right);
                 Debug.Log("User click RIGHT");
             }
             
             _isPressedButton = false;
         }
     }
     #endregion
     
     #region Choose Position
     //This method to do Where player is
     private void ChoosePosition(int paramPositionInfo, int paramWantedDirection)
     {        
         if(_canChangePosition)
         {
             Debug.Log("PosNumber : " + paramPositionInfo);
 
             if(paramPositionInfo == (int)LandStatus.OnCenter)
             {        
                 StartCoroutine(TakeMe(paramWantedDirection, paramPositionInfo));
             }
             
             else if(paramPositionInfo == (int)LandStatus.OnLeft && paramWantedDirection != (int)Directions.Left)
             {
                 StartCoroutine(TakeMe(paramWantedDirection, paramPositionInfo));
             }            
             
             else if(paramPositionInfo == (int)LandStatus.OnRight && paramWantedDirection != (int)Directions.Right)
             {
                 StartCoroutine(TakeMe(paramWantedDirection, paramPositionInfo));
             }
             
             else
                 _canChangePosition = false;
         }
     }
     #endregion
     
     #region Jump
     //This numerator to do jump player
     **IEnumerator Jump()**
     {
         if(!_onAir)
         {
             yield return StartCoroutine("JumpAction");
         }        
         yield return null;
     }
     #endregion
 
     #region JumpAction
     //This numerator to do finish jump action
     **IEnumerator JumpAction()**
     {
         Debug.Log(_characterGroundPosition);
         Debug.Log("Player is jumping");
         float _tempUpdatedTime;
         
         while(player.transform.position.y <= maxJumpMeter)
         {            
             _tempUpdatedTime = Time.deltaTime * (Time.timeScale / transitionDuration);
             player.transform.position += Vector3.up * _tempUpdatedTime * 50f;
             yield return null;
         }
     
         StartCoroutine("FallPlayer");
 
         yield return null;    
     }
     #endregion    
     
     #region FallPlayer
     //This numerator to do fall player
     **IEnumerator FallPlayer()**
     {
         Debug.Log("Fall player");
         float _tempUpdatedTime;
         
         while(player.transform.position.y >= _characterGroundPosition)
         {
             _tempUpdatedTime = Time.deltaTime * (Time.timeScale / transitionDuration);
             player.transform.position += Vector3.down * _tempUpdatedTime * 52f;
             yield return null;
         }        
         Debug.Log(player.transform.position.y);
         yield return null;
     }
     #endregion
     
     #region TakeMe
     //This numerator to do changing plyer's direction
     public IEnumerator TakeMe(int paramDirection, int paramPositionInfo)
     {        
         if(true)
         {
             Debug.Log("Take me : " + paramDirection + " " + "direction");
             Transform _wantedTransform = null;
             Vector3 _tempDirection = Vector3.zero;
             
             if(paramDirection == (int)Directions.Left)
             {
                 if(paramPositionInfo == (int)LandStatus.OnCenter) {_wantedTransform = playersLeft; _tempDirection = Vector3.left;}
                 else if(paramPositionInfo == (int)LandStatus.OnRight) {_wantedTransform = playersCenter; _tempDirection = Vector3.left;}                                
             }
             
             if(paramDirection == (int)Directions.Right)
             {
                 if(paramPositionInfo == (int)LandStatus.OnCenter) {_wantedTransform = playersRight; _tempDirection = Vector3.right;}
                 else if(paramPositionInfo == (int)LandStatus.OnLeft) {_wantedTransform = playersCenter; _tempDirection = Vector3.right;}                                
             }
             
             float _tempUpdatedTime = 0.0f;
             
             if(paramPositionInfo == (int)LandStatus.OnLeft || paramPositionInfo == (int)LandStatus.OnRight)
             {
                 _playerStatus = (int)Status.ChangePosition;
                 canJump = false;
                 
                 while (Math.Abs(player.transform.localPosition.x - playersCenter.position.x) >= _approachDistanceForCenter) 
                 {
                     _canChangePosition = false;
                     _playerStatus = (int)Status.Move;
                     _tempUpdatedTime = Time.deltaTime * (Time.timeScale / transitionDuration);
                     player.transform.position +=_tempDirection * _moveSpeed * myPlayerSpeed * _changeDirectionSpeed;
                     //player.transform.position = Vector3.Lerp(player.transform.position, _wantedTransform.position, _tempUpdatedTime);                
                     //player.transform.Translate(_wantedTransform.position * _tempUpdatedTime);
                     yield return null;
                 }
                 
                 canJump = true;
                 _playerStatus = (int)Status.Move;
             }
             
             else
             {
                 _playerStatus = (int)Status.ChangePosition;
                 canJump = false;
                 
                 while (Math.Abs(player.transform.localPosition.x - _wantedTransform.position.x) >= _approachDistance) 
                 {
                     _canChangePosition = false;
                     _playerStatus = (int)Status.Move;
                     _tempUpdatedTime = Time.deltaTime * (Time.timeScale / transitionDuration);
                     player.transform.position +=_tempDirection * _moveSpeed * myPlayerSpeed * _changeDirectionSpeed;
                     //player.transform.position = Vector3.Lerp(player.transform.position, _wantedTransform.position, _tempUpdatedTime);                
                     //player.transform.Translate(_wantedTransform.position * _tempUpdatedTime);
                     yield return null;
                 }
                 
                 canJump = true;
                 _playerStatus = (int)Status.Move;
             }
             
             _canChangePosition = true;
         }
     }
     #endregion
     
     #region FindPlayer's Land
     //For find where the player is
     private int FindPlayersLand()
     {
         Vector3 _myPosition = player.transform.position;
         int _tempPosition = _nullValue;
         
         if(Math.Abs(player.transform.localPosition.x - playersLeft.position.x) <= _approachDistance)//myPosition == playersLeft.position)
         {
             _tempPosition = (int)LandStatus.OnLeft;
             Debug.Log("Player on the left");
         }
         
         else if(Math.Abs(player.transform.localPosition.x - playersRight.position.x) <= _approachDistance)
         {
             _tempPosition = (int)LandStatus.OnRight;
             Debug.Log("Player on the right");
         }
         
         else if(Math.Abs(player.transform.localPosition.x - playersCenter.position.x) <= _approachDistanceForCenter)
         {
             _tempPosition = (int)LandStatus.OnCenter;
             Debug.Log("Player on the center");
         }
         
         //For first time
         else if(Math.Abs(Vector3.Distance(_myPosition, playersCenter.position)) == 0.0f)
         {
             _tempPosition = (int)LandStatus.OnCenter;
             Debug.Log("Player on the center");
         }
         
         else
         {
             _tempPosition = (int)LandStatus.OnMove;
             Debug.Log("Player on the moving");
         }
         
         return _tempPosition;
     }
     #endregion
     
     #region Move IENumetator
     // This numerator to do controll other numerators about moving
     public IEnumerator Move()
     {
         Debug.Log("Inside Move Numerator");        
         yield return new WaitForSeconds(GameManager.remainingTime);
         _playerStatus = (int)Status.Move;
         _canMove = true;
         _canChangePosition = true;
         Debug.Log("Move is started");
         StartCoroutine("MoveToSingle");
         StopCoroutine("Move");
     }
     #endregion
     
     #region MoveTo
     // This numerator to do take player from start position to end position
     public IEnumerator MoveToSingle()
     {
         if(_canMove)
         {
             while (_distance > 1) 
             {
                 this.transform.position += Vector3.forward * _moveSpeed * myPlayerSpeed;            
                 _playerDistance = GetMyDistance();
                 yield return null;
             }
                         
             _canMove = false;
             GameManager.FinishToGame();
             StopAllCoroutines();
         }
     }
     #endregion
     
     #region GetMyDistance
     //This method to do check player's distance from start to end points
     private float GetMyDistance()
     {
         float _result; 
         _result = Math.Abs(player.transform.position.z - _startPositionValue);
         return _result;
     }
     #endregion
     
     #region CalculateScore 
     //This method to do calculate user score
     public void CalculateScore()
     {
         Debug.Log("Bonus List Count : " + bonusList.Count.ToString());
         
         for(int i = 0; i < bonusList.Count; i++)
         {
             Debug.Log("---------Bonus List--------");
             Debug.Log("Name: " + bonusList[i].name);
             Debug.Log("Score Value: " + bonusList[i].scoreValue);
             Debug.Log("Each: " + bonusList[i].each);
             Debug.Log("---------------------------");
         }    
     }
     #endregion
 }