Diagnostics

Check engine light on? We read the code AND find the cause — professional diagnostics, not parts-cannon guessing.

What We Do

Check engine light diagnosis
Computer scan & live data testing
Electrical system diagnosis
Battery, starter & alternator testing (free)
Emissions & drivability issues
Pre-purchase inspections

Signs You Need It

Check engine light on or flashing
Car cranks but won't start
Battery keeps dying
Warning lights (ABS, traction, airbag)
Failed emissions test

Same Service, Nine Locations

Diagnostics at every one of our shops across Ann Arbor, Ypsilanti, Livonia, Taylor, Southfield, Redford, Canton — walk-ins welcome, financing available.

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Diagnostics Questions

A flashing check engine light — can I keep driving?

No — a flashing light means an active misfire that can destroy the catalytic converter. Reduce speed and get it in as soon as possible.

The parts store read my code for free. Why do I need diagnostics?

A code names the symptom, not the cause. P0420 might be a $40 sensor or a $1,400 converter — testing tells you which before you spend anything.