2019 Mazda Mazda3 — check-engine light turned itself off — still scan it?

Log the conditions before you spend. Move a coil or plug on the 2019 Mazda Mazda3 if it's cylinder-specific and see whether the code follows. If the cheap test changes it, stop and reassess. On “check-engine light turned itself off — still,” that was the fork that mattered for me. Was this after sitting overnight? I'd rather pay for diagnosis than a second guess-repair.

Ask what changed right before it started. Two 2019 Mazda Mazda3s can feel identical and have different causes, so measure before you copy someone else's repair. Save the big job until that test fails. Have you gotten a second quote in writing? Checking again after work.

OP update: scanned the 2019 Mazda Mazda3 again and still only have the one pending code, no new lights. Happens in gear, not in park, for what that's worth.

I wouldn't throw parts yet. Get a real battery/charging test on the 2019 Mazda Mazda3, not just resting voltage, before blaming a module. Save the big job until that test fails. This is from a 2019 Mazda Mazda3 in Bay Area. Time, temperature, and whether it's in gear are the notes that actually help a shop. Worth doing even if the car feels fine right now. Doing the boring step first on purpose.

This is usually cheaper to test than to guess. Swap the cheap/easy piece first on the 2019 Mazda Mazda3 and see if the fault moves. That's the branch I'd chase this week. I'd want a dollar figure or a measured spec, not 'should be fine.' Not driving it hard until I know more.