Check engine light diagnosis
beyond the code reader.

A code reader tells you something is wrong. A diagnosis tells you what.

A pulled fault code is the start of diagnosis, not the end. The same code can come from a dozen different root causes, and replacing parts based on the code itself is how owners end up with a $3,000 bill that didn’t fix the problem.

• Persistent check engine lightThe light comes back days or weeks after clearing.
• Codes the dealer or another shop cleared and they returnedA second opinion before you authorize expensive replacement work.
• Multiple codes at onceOften traces to a single root cause across multiple modules — not a coincidence.
• Codes paired with a driveability symptomMisfire, surging, no-start, stalling, rough idle, hesitation.

OEM diagnosis, not guesswork.

• Read every moduleNot just the engine. Modern vehicles have 70-100 modules; the cause of an engine code can live in the transmission, body controller, or fuel system.
• Live data + bidirectional controlWe watch sensor data while operating, and we command outputs to verify components individually.
• OEM-specific proceduresBMW, Mercedes, VAG, Tesla, Ford, GM, Toyota — we run the manufacturer-prescribed diagnostic path, not a generic flow chart.
• Written reportYou leave with a clear written diagnosis: what’s wrong, what it costs to fix, and what’s optional.

Diagnosis is the work — it has its own price.

We charge a diagnostic fee because diagnosis is time spent with manufacturer-grade tools narrowing down the actual fault. The fee covers that work regardless of whether you proceed with a repair — it is not refunded and is not applied toward repair costs.

• Call (210) 439-7905 for the current diagnostic feeSame fee applies whether your problem is straightforward or complex — we’re billing for time and tooling, not outcome.
• Estimate before chargeable repairIf diagnosis identifies a repair, you get a written estimate. Authorize and we proceed; decline and you owe only the diagnostic fee.