(CharacterController) Jumping from other script

Hello, in my game I'm using a character controller for the player, and I took the movement script from the unity scripting reference and modified it a little bit.

 using UnityEngine;
 using System.Collections;
 
 [RequireComponent(typeof(CharacterController))]
 public class PlayerMovementScript: MonoBehaviour {
 
     float speed;
     Vector3 moveDirection;
     CharacterController cc;
     public MouseLookScript mouseLookScript;
     public PlayerStatsScript playerStatsScript;
 
     void Start () {
         cc = GetComponent<CharacterController>();
     }
 
     void Update() {
         speed = playerStatsScript.speed/2f;
 
         if (cc.isGrounded) {
             moveDirection.x = Input.GetAxis("Horizontal");
             moveDirection.z = Input.GetAxis("Vertical");
             moveDirection = transform.TransformDirection(moveDirection);
             moveDirection *= speed;
         }
         else {
             moveDirection.x = 0f;
             moveDirection.z = 0f;
         }
         cc.Move(new Vector3(moveDirection.x, -9.8f, moveDirection.z) * Time.deltaTime);
     }
 
     void LateUpdate () {
         transform.eulerAngles = new Vector3(transform.rotation.x, mouseLookScript.currentYRotation, transform.rotation.z);
     }
 }

The problem is, in my game, there is no jump button, but if the player picks an item, he would be able to perform a single jump, however this jump is telleporting the player 9 units up instead of jumping, if I try to jump using the movement script (changing moveDirection.y) it works, but I need to make the jump from another script.

From the special ability script this is the important line:

 cc.Move(Vector3.up * 10f);

So can anyone tell me how to fix this issue? Thanks in advance.