2013 Infiniti G37 — coolant is old by age but mileage is low

Log the conditions before you spend. Get a real battery/charging test on the 2013 Infiniti G37, not just resting voltage, before blaming a module. If the cheap test changes it, stop and reassess. On “coolant is old by age but mileage,” that was the fork that mattered for me. Time, temperature, and whether it's in gear are the notes that actually help a shop. If it repeats twice more I'll book time.

If it were in my driveway, capture voltage while the 2013 Infiniti G37 is actually failing — after it restarts you've lost the clue. That's the branch I'd chase this week. That's the whole play. I already checked the easy fluid levels.

Ask what changed right before it started. Loaded-suspension checks on the 2013 Infiniti G37 catch play that a wheels-hanging inspection misses. If the cheap test changes it, stop and reassess. Write the result down so the next test isn't a repeat of the last one. Make the next action something you can finish this week. Video is ugly but it shows the hesitation.

This is usually cheaper to test than to guess. Two 2013 Infiniti G37s can feel identical and have different causes, so measure before you copy someone else's repair. Don't erase codes until someone who can help has seen them. Stop there until you know. A day of patience here is cheaper than a wrong part. Wrote this up on my lunch break.