Why does Dons Automotive charge to diagnose my “check engine” light when Autozone will do it for free?
There’s a big difference here. Autozone will pull a fault code from the engine computer in your vehicle. This code is an error message referring to a fault in one of many engine control systems. This can be done with a $79 code reader. They present a generic list of possible causes that in no way takes into account specifics of your make and model. If parts are replaced based on this “diagnosis” alone they typically will NOT fix the problem. We have several thousands of dollars invested in service information, sophisticated scan tools that allow us to read a datastream from the vehicle and professional experience to isolate and fix the problem. Sometimes the diagnosis is relatively easy and straightforward, sometimes considerable testing will be required.
