Symptom guide · Glass Box Diagnostics
The light means some module logged a fault — it does not mean you owe $2,000 for a part. Auto-parts-store free testing reads the generic code only; the honest next step is knowing what that code actually proves before anyone touches a wrench.
Read the code, quote the part the code name mentions, skip the verification test. If the code was caused by something upstream, it returns after you have paid.
Typical guess-and-swap cost: $200–$2,500 depending on which part the code name points at
Pull the code, then prove it: live data, freeze frame, misfire counters, fuel trims, component tests. A 20-minute scan-and-verify tells you which of the several causes is actually yours.
We come to you — Canyon Lake, San Antonio & Austin. Written report with root cause — see a sample.