Canyon Lake • San Antonio • Austin

We Diagnose.
We Don't Upsell Repairs.

The person diagnosing your car shouldn't profit from fixing it. We removed the conflict. Factory-level tools, honest reports, zero pressure.

hello@glassboxdiag.com

Same Car. Same Problem. Different Outcomes.

Check engine light

Typical Shop

"You need new catalytic converters. $2,800."

Glass Box

O2 sensor heater fault — the cat is fine. $180 sensor, 30-minute fix.

Saved: $2,620

Battery keeps dying

Typical Shop

"You need a new battery and alternator." (Problem persists)

Glass Box

340mA parasitic draw traced to trunk light switch. $12 part.

Saved: $800+

Transmission slipping

Typical Shop

"Transmission rebuild — $4,500."

Glass Box

Range sensor out of calibration. Recalibrated with scan tool. $0 in parts.

Saved: $4,500

How It Works

Book Online

Select service, describe symptoms, choose a time.

We Come to You

Mobile service at your location, 7 days a week.

We Diagnose

Factory tools. Root cause. No upsell.

You Get the Report

Detailed findings. You decide what happens next.

Ready for Honest Diagnostics?

Mobile service. 7 days a week. Texas Hill Country.