Serialization of the EF model with cyclic dependency

Question

I'm trying to serialize the database model. But there is an error.

Here is my model:

public class Equipment
    {
        public int Id { get; set; }
        //Двигатель
        [Required]
        [Display(Name = "Двигатель")]
        public int Engine { get; set; }
        //Количество лошадиных сил
        [Required]
        [Display(Name = "Мощность")]
        public int Power { get; set; }
        //Год выпуска
        [Required]
        [Display(Name = "Год выпуска")]
        public int ReleaseYear { get; set; }
        //Тип привода
        [Required]
        [Display(Name = "Тип привода")]
        public string DriveType { get; set; }
        //КПП
        [Required]
        [Display(Name = "КПП")]
        public string Transmission { get; set; }
        //Кузов
        [Required]
        [Display(Name = "Кузов")]
        public string Body { get; set; }
        //Максимальная скорость
        [Required]
        [Display(Name = "Максимальная скорость")]
        public int MaxSpeed { get; set; }
        //Вес
        [Required]
        [Display(Name = "Вес")]
        public int Weight { get; set; }
        //Бак
        [Required]
        [Display(Name = "Бак")]
        public int MaxFuelVolume { get; set; }
        //Цвет автомобиля
        [Required]
        [Display(Name = "Цвет")]
        public string Color { get; set; }
        //Изорбражение автомобиля
        [Required]
        [Display(Name = "Изображение автомобиля")]
        public string Picture { get; set; }

        public int CarModelId { get; set; }
        public virtual CarModel CarModel { get; set; }
        public virtual ICollection<Car> Cars { get; set; }

        public Equipment()
        {
            Cars = new List<Car>();
        }
    }

Here is my code in the controller for serialization:

return Json(JsonConvert.SerializeObject(car.Equipment));

This is what error produces:

Self referencing loop detected with type 'System.Data.Entity.DynamicProxies.Equipment_4B2DAA6CED521984C9D15F5FEA2BB989D5DB7F80683721A0FC847726CB1C9ACB'. Path 'CarModel.Equipments'.

Here is the class that swears:

public class CarModel
    {
        public int Id { get; set; }

        [Display(Name = "Модель")]
        public string ModelName { get; set; }

        public int MarkId { get; set; }
        public virtual Mark Mark { get; set; }

        public virtual ICollection<Equipment> Equipments { get; set; }

        public CarModel()
        {
            Equipments = new List<Equipment>();
        }
    }

I tried to connect System.web.script.serialization and set the script ignore attribute to

public virtual CarModel CarModel { get; set; }
public virtual ICollection<Car> Cars { get; set; }

In equipment class and on

public virtual ICollection<Equipment> Equipments { get; set; }

n the CarModel class, it's still the same error.

Please tell me how to avoid this error? And how can you serialize a model with cyclic dependency?

ajax request:

$('#autoList').on('change', function () {
        var ddlAuto = $('#autoList').val();
        if (!ddlAuto || ddlAuto === '')
            return false;

        $.ajax({
            type: "POST",
            url: "/Administration/GetCarInfo",
            data: {
                "carId": ddlAuto
            },
            success: function (data) {
                alert('ОК');
            }
        });
    });

But under one condition, it was possible to serialize, though it was serialized not into an object but into a string.

The result of serialization if in the controller to write

return Json(JsonConvert.SerializeObject(car.Equipment, Formatting.Indented, new JsonSerializerSettings
            {
                PreserveReferencesHandling = PreserveReferencesHandling.Objects
            }));

"{
  "$id": "1",
  "CarModel": {
    "$id": "2",
    "Equipments": [
      {
        "$ref": "1"
      }
    ],
    "Mark": {
      "$id": "3",
      "CarModels": [
        {
          "$ref": "2"
        },
        {
          "$id": "4",
          "Equipments": [
            {
              "$id": "5",
              "CarModel": {
                "$ref": "4"
              },
              "Cars": [
                {
                  "$id": "6",
                  "Equipment": {
                    "$ref": "5"
                  },
                  "Orders": [
                    {
                      "$id": "7",
                      "Cars": {
                        "$ref": "6"
                      },
                      "Clients": {
                        "$id": "8",
                        "Orders": [
                          {
                            "$ref": "7"
                          },
                          {
                            "$id": "9",
                            "Cars": {
                              "$id": "10",
                              "Equipment": {
                                "$id": "11",
                                "CarModel": {
                                  "$ref": "4"
                                },
                                "Cars": [
                                  {
                                    "$ref": "10"
                                  }
                                ],
                                "Id": 30,
                                "Engine": 2500,
                                "Power": 170,
                                "ReleaseYear": 2011,
                                "DriveType": "Передний",
                                "Transmission": "Автомат",
                                "Body": "Седан",
                                "MaxSpeed": 220,
                                "Weight": 1800,
                                "MaxFuelVolume": 80,
                                "Color": "Чёрный"

I tried to do something else

return Json(JsonConvert.SerializeObject(car.Equipment, Formatting.Indented, new JsonSerializerSettings
            {
                ReferenceLoopHandling = ReferenceLoopHandling.Ignore
            }));

Then an error occurs:

"System.OutOfMemoryException"

Please tell me what am I doing wrong? How can I serialize my model into an object to continue working with it?