Using shared service data share between two components in Angular2

Question

I am working on angular 2 application with open layer map. in that i need to share the location coordinate from one components to other components using share services.

searchcomponents.ts

 bounds: any;
placesChanged() {
    var places = this.searchBox.getPlaces();

    if (places == null) return;
    if (places == undefined) return;
    if (places.length == 0) return;

    this.searchResultsSource.clear();

    this.bounds = new google.maps.LatLngBounds();
    // For each place, get the icon, name and location.
    places.forEach(this.processPlace.bind(this));

    // if the drawn result(s) is only one
    if (this.searchResultsSource.getFeatures().length == 1) {
        var singleFeature = this.searchResultsSource.getFeatures()[0];
        this.pos = singleFeature.getGeometry().getCoordinates();
        console.log(this.pos ,"hanumanh" );
        this.service.setUrlHistoryObj(this.pos);
    }

i want to share pos value to other components. this is my service code

Search.services.ts

import {Injectable} from '@angular/core';
import { Subject }    from 'rxjs/Subject';

@Injectable()
export class SearchService {
public pos : string;
public invokeEvent:Subject<any> = new Subject<string>();
constructor() {   
this.pos="";
 }
public setUrlHistoryObj(val: string): void {
        this.pos = val;
        console.log(val);
    }
    public getUrlHistoryObj(): string {
        return this.pos;    
  }

in this i am getting the pos value as geocoordinate and i want to share that pos value to other components.

Buffer.components.ts

value1: string;

constructor(
    private urlHistoryService:SearchService) {

    this.value1 = this.urlHistoryService.getUrlHistoryObj();
   // this.value1 = this.urlHistoryService.setUrlHistoryObj();

}

i am getting error undefined. please help me.