Performance DIY by DIY Guru

A check engine light diagnosis can cost $0 at many auto-parts stores and repair shops , while a professional diagnostic scan at a mechanic typically costs around $50 to $150 . However, a free code scan usually tells you what fault code was stored —not necessarily why the problem happened or what the repair will cost. How much does a check engine light diagnosis cost? The price depends on where you go and how deeply the vehicle needs to be tested. In most cases, you should start with the cheapest option: a free OBD-II code scan . If the code points to a problem that requires further testing, then paying a mechanic for a complete diagnosis may be worthwhile. Here is how the options generally compare: Diagnosis option Typical cost What you get Auto-parts store scan Free Basic trouble codes DIY OBD-II scanner $20–$100+ Codes and basic live data Independent mechanic $50–$150 Professional diagnosis Dealership $100–$200+ Factory-level diagnostics Complex electrical diagnosis $150–$300+ Advanc...