ON-SITESan Antonio · Bulverde · New Braunfels · Boerne · Schertz · Selma · Universal CityREMOTENationwide US & Into CanadaCERTIFIEDNASTF VSP REGISTERED · OEM ToolingHOTLINE(210) 439-7905ON-SITESan Antonio · Bulverde · New Braunfels · Boerne · Schertz · Selma · Universal CityREMOTENationwide US & Into CanadaCERTIFIEDNASTF VSP REGISTERED · OEM ToolingHOTLINE(210) 439-7905
▸ VEHICLE OWNERS · 01 / RETAIL TRACK

A real diagnosis before you authorize the work.

Spot-On Automotive Diagnostics serves individual vehicle owners in-shop only, by appointment, at 4715 N Stahl Park, Suite 105, San Antonio, TX 78217. Specialty focus on module failures, complex electrical, ADAS recalibration after collision or windshield replacement, key & immobilizer service, and hybrid/EV diagnostics. We do not offer mobile service to retail customers — mobile dispatch is a trade-only offering for repair shops, body shops, dealerships, and fleets.

Eight specialty tracks. All in-shop.

Most general repair shops can change parts. A diagnostic specialist tells you which parts actually need changing — with manufacturer-grade tools, not a code reader and a guess. Each tile links to a dedicated retail service page.

01 / RETAIL
Check Engine Light Diagnosis
Real diagnosis with manufacturer-grade tools. Includes persistent fault codes, no-start conditions, and codes that come back after the dealer cleared them.
02 / RETAIL
Second-Opinion Diagnostics
Quoted $3,000 for a mystery code? Bring the vehicle and the other shop's paperwork. We verify what's actually wrong before you authorize the work.
03 / RETAIL
ADAS Calibration
Required after collision repair, windshield replacement, alignment, or sensor replacement. Static + dynamic to OEM spec.
04 / RETAIL
Key & Immobilizer Services
All-keys-lost, add-a-key, immobilizer reset. NASTF VSP credentialed for legal access to manufacturer security systems.
05 / RETAIL
Electrical Diagnostics
Parasitic draws, complex multi-module communication issues. The work that ends with a dealer saying “we can't replicate it.”
06 / RETAIL
Hybrid & EV Diagnostics
High-voltage system work most independent shops won't touch. L3 Light Duty Hybrid/EV Specialist certified.
07 / RETAIL
Specialty Services
Module programming, EEPROM, cluster odometer correction, VIN correction, immobilizer disable, second-opinion electrical — the depth most shops can't reach.
08 / RETAIL
Mercedes Electronic Steering Lock
Mercedes won't start, key won't turn? That is usually the electronic steering lock (ESL / ELV). In-shop diagnosis and repair, or the W204/W207/W212 mail-in emulator.
09 / RETAIL
Used ECM, PCM & BCM Programming
Bought a used or junkyard engine computer and the car won't start? We program and clone used modules to your vehicle — clone or program, we pick the right route.
10 / MAIL-IN
Mail-In Module Programming
Can't get the car here? Ship us the module (ECM, PCM, BCM, ESL) from anywhere in the US & Canada — we program it on the bench and ship it back. A trade-track service open to shops and vehicle owners alike.

Four steps from booking to a written repair plan.

We work on one vehicle at a time, properly. The process below is the same whether you're bringing us a check-engine light, a complex electrical fault, or a second-opinion on a dealer estimate.

01
Book an appointment

Use the online schedule form or call (210) 439-7905. Tell us year/make/model, what the vehicle is doing, and bring any prior estimates or paperwork.

02
Drop the vehicle off

Drop-off at 4715 N Stahl Park, Suite 105, San Antonio. Most diagnoses complete same-day or next-day depending on platform complexity. Please bring the vehicle in actively faulting.

03
We diagnose with OEM-grade tools

Real diagnosis — the same manufacturer software the dealer runs, plus engineering-level access for jobs the dealer can't reach. No parts cannon.

04
Written repair plan & estimate

You get a clear written report of what's wrong, what it'll cost to fix, and what's optional. Authorize and we proceed; decline and you owe only the diagnostic fee.

When the dealer can't replicate it. When the local shop has run out of ideas.

Most repair shops and even most dealerships are built around volume — brake jobs, alignments, scheduled maintenance, and high-frequency repairs. A diagnostic specialist is built around the work that lives outside that volume curve.

General repair shops and dealerships are excellent at the work they see every day. Where they struggle is the long-tail — the complex electrical fault the standard scan tool can't isolate, the module failure that throws unrelated codes, the ADAS calibration that requires OEM-specific targets and a level floor, the immobilizer issue that needs NASTF-credentialed gateway access.

Spot-On's lead technician holds ASE Master Automobile, ASE Master Medium/Heavy Truck, ASE Advanced Specialist L1–L4 (including ADAS), and ASE B5 Mechanical & Electrical Components (Collision), plus an active NASTF Vehicle Security Professional registration and 11 Ford FACT credentials. We run manufacturer-authentic software — the same the dealer uses — plus engineering-level tooling the dealer doesn't have access to.

We don't do brake jobs. We don't do oil changes. We do the work that ends with another shop saying “we can't figure it out” — and we do it without the dealership wait list or the parts-cannon estimate.

Most major platforms. Domestic, Asian, European.

We cover 40+ OEM platforms across light-duty, medium-duty, and heavy-duty applications. Click your make for platform-specific information; call us if you don't see it listed.

The three questions we hear most.

Common questions from individual vehicle owners. The full retail-track FAQ has more.

Do you come to me, or do I bring my car to you?

Vehicle owners bring their vehicle to our shop at 4715 N Stahl Park, Suite 105, San Antonio, TX 78217. We work on one vehicle at a time, properly. We do not dispatch mobile service to individual vehicle owners under any circumstances — mobile dispatch is a B2B-only offering for repair shops, body shops, dealerships, and fleets.

Another shop or the dealer quoted me $3,000+ — can you give a second opinion?

Yes. Second-opinion diagnostics is one of the things we do most. Bring the vehicle in by appointment with whatever documentation the other shop or dealer provided. We'll verify what's actually wrong with manufacturer-grade tools before you authorize any expensive work.

What if the symptom isn't happening when I drop the car off?

Please bring the vehicle in actively faulting. Tell us everything you know — when it happens, what changes, recent work. Reproducibility on arrival is the fastest, most cost-effective path to a real answer; faults we can capture faults that pop up only under specific conditions.

Read the full retail FAQ →  ·  or call (210) 439-7905

▸ READY TO BOOK

Book an appointment.

In-shop drop-off, by appointment only. Tell us what the vehicle is doing and we'll have the right tools and software ready before you arrive.