[Dragony92]

pawn Code:

new GodMode[MAX_PLAYERS];
//Under OnGameModeInit
SetTimer("AutoR", 2000, true);

//Under your Command Godmode (ON)
GodMode[playerid] = 1;

//Under your Command Godmode (OFF)
GodMode[playerid] = 0;

forward AutoR(playerid);
public AutoR(playerid)
{
    if(IsPlayerInAnyVehicle(playerid) && GodMode[playerid] == 1)
    {
        new vid = GetPlayerVehicleID(playerid);
        RepairVehicle(vid);
    }
    return 1;
}

And also you can make public like this

pawn Code:

public AutoR(playerid)
{
    if(IsPlayerInAnyVehicle(playerid) && GodMode[playerid] == 1)
    {
        new vid = GetPlayerVehicleID(playerid);
        new Float:health;
        GetVehicleHealth(vid, health);
        if(health <999) // or lower....
        {
            RepairVehicle(vid);
        }   
    }
}