I may just be paranoid, but would suggest that you read this post and the links therein. Executive summary as it applies here: you are courting danger by relying on the order of execution: there isn’t a reliable way to know in which order your two (ngModelChange) listeners fire, so you cannot safely rely on the value of this.car_id inside carChangeEvent: if you absolutely insist on writing code with multiple (ngModelChange) listeners, ensure that your code works independently of which one fires first (such as using event instead of this.car_id in carChangeEvent).