diff --git a/tests/unit/Services/cars.test.ts b/tests/unit/Services/cars.test.ts
index 743f443..c7410d0 100644
--- a/tests/unit/Services/cars.test.ts
+++ b/tests/unit/Services/cars.test.ts
@@ -14,13 +14,17 @@ const reqCar: ICar = {
   seatsQty: 5,
 };
 
+const invalid = { message: 'Invalid mongo id' };
+const notFound = { message: 'Car not found' };
+const id = '6348513f34c397abcad040b2';
+
 describe('Car Service', function () {
   afterEach(function () {
     sinon.restore();
   });
 
   it('should create a car', async function () {
-    sinon.stub(Model, 'create').resolves({ id: '6348513f34c397abcad040b2', ...reqCar });
+    sinon.stub(Model, 'create').resolves({ id, ...reqCar });
 
     const carService = new CarService();
     const car = await carService.create(reqCar);
@@ -31,26 +35,34 @@ describe('Car Service', function () {
     expect(car).to.have.property('year');
     expect(car).to.have.property('color');
     expect(car).to.have.property('status');
-    expect(car).to.be.deep.equal({ id: '6348513f34c397abcad040b2', ...reqCar });
+    expect(car).to.be.deep.equal({ id, ...reqCar });
+  });
+
+  it('not exists car', async function () {
+    sinon.stub(Model, 'create').resolves(null);
+
+    const carService = new CarService();
+    const car = await carService.create(reqCar);
+
+    expect(car).to.be.deep.equal(null);
   });
 
   it('test method GET with function "findAll"', async function () {
-    sinon.stub(Model, 'find').resolves([{ id: '6348513f34c397abcad040b2', ...reqCar }]);
+    sinon.stub(Model, 'find').resolves([{ id, ...reqCar }]);
 
     const carService = new CarService();
     const car = await carService.findAll();
 
-    expect(car).to.be.deep.equal([{ id: '6348513f34c397abcad040b2', ...reqCar }]);
+    expect(car).to.be.deep.equal([{ id, ...reqCar }]);
   });
 
   it('test method GET with function "finById" when id exists', async function () {
-    sinon.stub(Model, 'findOne').resolves({ id: '6348513f34c397abcad040b2', ...reqCar });
+    sinon.stub(Model, 'findOne').resolves({ id, ...reqCar });
 
     const carService = new CarService();
-    const id = '6348513f34c397abcad040b2';
     const car = await carService.findById(id);
 
-    const response = { id: '6348513f34c397abcad040b2', ...reqCar };
+    const response = { id, ...reqCar };
 
     expect(car).to.be.deep.equal({ status: 200, response });
   });
@@ -59,28 +71,22 @@ describe('Car Service', function () {
     const carService = new CarService();
     const car = await carService.findById('1');
 
-    const response = { message: 'Invalid mongo id' };
-
-    expect(car).to.be.deep.equal({ status: 422, response });
+    expect(car).to.be.deep.equal({ status: 422, response: invalid });
   });
 
   it('test method GET with function "finById" when car  not exists', async function () {
     sinon.stub(Model, 'findOne').resolves(null);
 
     const carService = new CarService();
-    const id = '6348513f34c397abcad040b2';
     const car = await carService.findById(id);
 
-    const response = { message: 'Car not found' };
-
-    expect(car).to.be.deep.equal({ status: 404, response });
+    expect(car).to.be.deep.equal({ status: 404, response: notFound });
   });
 
   it('test method PUT with function "updateById" when id exists', async function () {
-    sinon.stub(Model, 'findOneAndUpdate').resolves({ id: '6348513f34c397abcad040b2', ...reqCar });
+    sinon.stub(Model, 'findOneAndUpdate').resolves({ id, ...reqCar });
 
     const carService = new CarService();
-    const id = '6348513f34c397abcad040b2';
     const car = await carService.updateById(id, reqCar);
 
     expect(car).to.be.an('object');
@@ -92,4 +98,52 @@ describe('Car Service', function () {
     expect(car).to.be.deep.equal({ status: 200, 
       response: { id, ...reqCar } });
   });
+
+  it('test method PUT with function "updateById" when id is not valid', async function () {
+    const carService = new CarService();
+    const car = await carService.updateById('1', reqCar);
+
+    expect(car).to.be.deep.equal({ status: 422, response: invalid });
+  });
+
+  it('test method PUT with function "updateById" when car not exists', async function () {
+    sinon.stub(Model, 'findOneAndUpdate').resolves(null);
+
+    const carService = new CarService();
+    const car = await carService.updateById(id, reqCar);
+
+    expect(car).to.be.deep.equal({ status: 404, response: notFound });
+  });
+
+  it('test method DELETE with function "deleteById" when id exists', async function () {
+    sinon.stub(Model, 'findOneAndDelete').resolves({ id, ...reqCar });
+
+    const carService = new CarService();
+    const car = await carService.deleteById(id);
+
+    expect(car).to.be.an('object');
+    expect(car.response).to.have.property('id');
+    expect(car.response).to.have.property('model');
+    expect(car.response).to.have.property('year');
+    expect(car.response).to.have.property('color');
+    expect(car.response).to.have.property('status');
+    expect(car).to.be.deep.equal({ status: 204, 
+      response: { id, ...reqCar } });
+  });
+
+  it('test method DELETE with function "deleteById" when id is not valid', async function () {
+    const carService = new CarService();
+    const car = await carService.deleteById('1');
+
+    expect(car).to.be.deep.equal({ status: 422, response: invalid });
+  });
+
+  it('test method DELETE with function "deleteById" when car not exists', async function () {
+    sinon.stub(Model, 'findOneAndDelete').resolves(null);
+
+    const carService = new CarService();
+    const car = await carService.deleteById(id);
+
+    expect(car).to.be.deep.equal({ status: 404, response: notFound });
+  });
 });
\ No newline at end of file
diff --git a/tests/unit/Services/motorcycle.test.ts b/tests/unit/Services/motorcycle.test.ts
index b1ea33d..6faf4dd 100644
--- a/tests/unit/Services/motorcycle.test.ts
+++ b/tests/unit/Services/motorcycle.test.ts
@@ -14,9 +14,16 @@ const reqMotorcycle: IMotorcycle = {
   engineCapacity: 1.000,
 };
 
+const notFound = { message: 'Motorcycle not found' };
+const invalid = { message: 'Invalid mongo id' };
+
 const id = '6348513f34c397abcad040b2';
 
 describe('Motorcycle Service', function () {
+  afterEach(function () {
+    sinon.restore();
+  });
+
   it('should create a motorcycle', async function () {
     sinon.stub(Model, 'create').resolves({ id, ...reqMotorcycle });
 
@@ -32,6 +39,15 @@ describe('Motorcycle Service', function () {
     expect(motorcycle).to.be.deep.equal({ id, ...reqMotorcycle });
   });
 
+  it('should not create a motorcycle', async function () {
+    sinon.stub(Model, 'create').resolves(null);
+
+    const motorcycleService = new MotorcycleService();
+    const motorcycle = await motorcycleService.create(reqMotorcycle);
+
+    expect(motorcycle).to.be.deep.equal(null);
+  });
+
   it('should find all motorcycles', async function () {
     sinon.stub(Model, 'find').resolves([{ id, ...reqMotorcycle }]);
 
@@ -41,7 +57,7 @@ describe('Motorcycle Service', function () {
     expect(motorcycle).to.be.deep.equal([{ id, ...reqMotorcycle }]);
   });
 
-  it('should find a motorcycle by id', async function () {
+  it('should find a motorcycle by id when id exists', async function () {
     sinon.stub(Model, 'findOne').resolves({ id, ...reqMotorcycle });
 
     const motorcycleService = new MotorcycleService();
@@ -52,7 +68,23 @@ describe('Motorcycle Service', function () {
     expect(motorcycle).to.be.deep.equal({ status: 200, response });
   });
 
-  it('should find a motorcycle by id and update', async function () {
+  it('should find a motorcycle by id when id is not valid', async function () {
+    const motorcycleService = new MotorcycleService();
+    const motorcycle = await motorcycleService.findById('1');
+
+    expect(motorcycle).to.be.deep.equal({ status: 422, response: invalid });
+  });
+
+  it('should find a motorcycle by id when id does not exist', async function () {
+    sinon.stub(Model, 'findOne').resolves(null);
+
+    const motorcycleService = new MotorcycleService();
+    const motorcycle = await motorcycleService.findById(id);
+
+    expect(motorcycle).to.be.deep.equal({ status: 404, response: notFound });
+  });
+
+  it('should find a motorcycle by id and update when id exists', async function () {
     sinon.stub(Model, 'findOneAndUpdate').resolves({ id, ...reqMotorcycle });
 
     const motorcycleService = new MotorcycleService();
@@ -62,4 +94,47 @@ describe('Motorcycle Service', function () {
 
     expect(motorcycle).to.be.deep.equal({ status: 200, response });
   });
+
+  it('should find a motorcycle by id and update when id is not valid', async function () {
+    const motorcycleService = new MotorcycleService();
+    const motorcycle = await motorcycleService.updateById('1', reqMotorcycle);
+
+    expect(motorcycle).to.be.deep.equal({ status: 422, response: invalid });
+  });
+
+  it('should find a motorcycle by id and update when id does not exist', async function () {
+    sinon.stub(Model, 'findOneAndUpdate').resolves(null);
+
+    const motorcycleService = new MotorcycleService();
+    const motorcycle = await motorcycleService.updateById(id, reqMotorcycle);
+
+    expect(motorcycle).to.be.deep.equal({ status: 404, response: notFound });
+  });
+
+  it('should find a motorcycle by id and delete when id exists', async function () {
+    sinon.stub(Model, 'findOneAndDelete').resolves({ id, ...reqMotorcycle });
+
+    const motorcycleService = new MotorcycleService();
+    const motorcycle = await motorcycleService.deleteById(id);
+
+    const response = { id, ...reqMotorcycle };
+
+    expect(motorcycle).to.be.deep.equal({ status: 204, response });
+  });
+
+  it('should find a motorcycle by id and delete when id is not valid', async function () {
+    const motorcycleService = new MotorcycleService();
+    const motorcycle = await motorcycleService.deleteById('1');
+
+    expect(motorcycle).to.be.deep.equal({ status: 422, response: invalid });
+  });
+
+  it('should find a motorcycle by id and delete when id does not exist', async function () {
+    sinon.stub(Model, 'findOneAndDelete').resolves(null);
+
+    const motorcycleService = new MotorcycleService();
+    const motorcycle = await motorcycleService.deleteById(id);
+
+    expect(motorcycle).to.be.deep.equal({ status: 404, response: notFound });
+  });
 });
\ No newline at end of file