Pep Boys and Autozone offer different types of free car diagnostic tests. Pep Boys offers a free battery test, check engine light code retrieval service, windshield wiper inspection and brake inspection. If the windshield wipers need to be replaced, Pep Boys replaces them for free.
Autozone provides its free car diagnostic tests while the driver is still in the vehicle. This includes checking the starter, battery, alternator and voltage regulator. A complete starting and charging systems test is also available. Some locations also test the throttle position sensors, control modules, coils and voltage regulators. No appointment is needed for these services.