Electronic Diagnostics
Check-engine light on? We read the real codes and interpret them — a code is a clue, not a diagnosis.
A check-engine light is your car trying to tell you something — and ignoring it usually turns a small fix into a big one. Tom's Mobil Service reads the actual story behind that light: not just the code, but what's causing it. Roseville drivers bring us their warning lights and weird symptoms because we diagnose it right the first time. Call 651-489-7807 or book online.
Symptoms worth getting checked
- Check-engine, ABS, or other dash warning lights
- Rough idle, stalling, or hard starts
- Loss of power or poor acceleration
- A drop in fuel economy
- Strange noises, smells, or vibrations
- Hesitation or surging while driving
A real diagnosis, not just a code read
A parts-store code reader tells you a light is on; it doesn't tell you why. We use professional scan tools and proven test procedures to trace the actual fault — so you fix the cause, not just the symptom.
- Full scan of engine and related systems
- Live data and component testing
- Pinpoint the root cause, not just the code
- A clear written explanation of what's wrong
What we diagnose and repair
- Check-engine and warning-light causes
- Sensors (oxygen, MAF, crank/cam, and more)
- Ignition, fuel, and emissions issues
- Drivability problems: stalling, misfires, hesitation
- Electrical and computer faults
Why a proper diagnosis saves money
Guessing at parts is expensive. Pinpointing the real fault means you pay for the fix you actually need — once. We'd rather find it right than throw parts at it.
All makes and models
Domestic, Asian, and European vehicles, with the tools and know-how to read modern systems accurately.
Honest, upfront pricing
- A clear diagnosis before any repair
- A real estimate, no surprises
- Straight talk on what's urgent
Why Roseville drivers choose Tom's Mobil Service
A 4.6-star reputation for getting to the bottom of it. Serving St. Paul, Maplewood, Little Canada, Falcon Heights, Oakdale.
Book a diagnostic
Light on the dash or something not feeling right? Call Tom's Mobil Service at 651-489-7807 or book online.
Frequently asked questions
My check-engine light is on — is it safe to drive?
Sometimes, but a flashing light means stop soon. Get it scanned promptly either way. Call 651-489-7807.
Can't I just read the code at the parts store?
That tells you a light is on, not why. We test to find the actual cause before you spend on parts.
How much does a diagnostic cost in Roseville?
We'll tell you upfront before we start. The diagnosis pays for itself by avoiding wrong-part guesses.
Why did my light come back on after I cleared it?
Because the underlying issue wasn't fixed — clearing a code doesn't fix the fault.
Do you diagnose electrical and computer problems?
Yes, including sensors, modules, and wiring faults.
Other services you might need
Full-Service Gas
Stay in the car. An attendant pumps your gas, checks your oil, and cleans the windshield.
Brake Repair
Grinding, squealing, or a soft pedal? We fix pads, rotors, calipers & fluid — quoted before we touch anything.
A/C & Heating
Blowing warm in July or cold in January? We find the actual fault instead of just topping it off.
Wheel Alignment
Car pulling or tires wearing unevenly? Precision alignment for better handling and longer tire life.
Tire Services
New tires, rotations, balancing & flat repair — the right tire for your car and budget, no upsell.
Electrical Repair
Dead battery, dim lights, or electrical gremlins? Real diagnostics, no guessing.
Electronic Diagnostics across our service area
Ready to get your car looked at?
Schedule online or call 651-489-7807.