Check engine light on?
Don’t guess what it means. A full diagnostic at JM Auto Repair is $60 on your first visit (regularly $140), and we tell you exactly what’s wrong before any work starts.
What a real diagnostic includes
A parts-store scanner gives you a code. A diagnostic tells you why the code happened. We road-test the car, scan every module, check the sensors and wiring the code points to, and confirm the actual cause, so you fix the problem once instead of paying for guesses.
What it costs
RepairPal’s national estimate for a check engine light diagnosis is $125–$183 (September 2026), and dealerships often charge more. At JM, your first-visit diagnostic or inspection is a flat $60 (regularly $140). Estimates for the repair itself are always free, and you approve the price before any work begins.
“The parts store read my code for free. Why pay?”
Free code readers are fine for what they are: they name the code. But one code can have five different causes at five very different prices. Replacing parts until the light goes off usually costs more than one honest diagnosis. We find the cause first, then you decide what to do.
Common reasons the light comes on
Loose gas cap, oxygen sensor, catalytic converter efficiency, misfires, EVAP leaks, mass-airflow sensor. Some are cheap fixes; some matter for smog. If the light is flashing, stop driving and call us. A flashing light means an active misfire that can damage the catalytic converter.
$60 on your first visit at JM Auto Repair (regularly $140). RepairPal’s national estimate is $125–$183. The price is flat and you know it before we start.
If the cause was temporary, like a loose gas cap, it can clear after several drive cycles. If it stays on, the fault is still active and worth checking.
A steady light: usually yes, but get it checked soon. Some faults quietly damage the catalytic converter. A flashing light: no. Pull over and call (831) 387-7181.
No. A code scan ($40 at JM) reads the stored codes. A diagnostic ($140, or $60 on your first visit) tests the parts and wiring the code points to and confirms the real cause.
Yes, parts stores will read the code for free. That tells you the code, not the cause. Our diagnostic finds why the code set, so you only pay for the repair your car actually needs.