Cylinder 1 misfire detected

What the code means

The controller detected repeated combustion-speed variation associated with cylinder 1.

Severity and driving

Urgent if flashing or running severely rough

Plausible causes

Spark or ignition fault
Injector or wiring fault
Vacuum/air leak
Low compression

Next checks

Record whether it occurs cold, hot, or under load
Check for related fuel-trim or injector codes
Arrange cylinder-specific testing before replacing parts

Source and boundary

Code structure follows SAE J2012. Manufacturer-specific definitions, pinpoint tests, wiring, torque, fluids, and repair procedures require authoritative information for the exact vehicle.

SAE J2012 Diagnostic Trouble Code DefinitionsReviewed 2026-08-13

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