Car diagnostic tests can scan components and a car’s integrated systems for errors or malfunctions before they become truly dangerous. Let’s break down what car diagnostic tests are and examine their ...

Kelley Blue Book How to test drive a car: Your complete checklist A test drive is your chance to determine if a vehicle fits your lifestyle, performs well, and if it is worthy of a major expense.

Open the ignition switch to the On position without starting the car. This will initialize the Key On, Engine Off (KOEO) test. Watch the Check Engine light closely because it will begin to flash.