iPhone 16 Pro and 16 Pro Max restarting every 3 minutes

If your iPhone 16 Pro or 16 Pro Max restarts about every 3 minutes, often with a short pink or purple flash, its power controller (SMC) has lost one of its sensors. The panic log names which one - here is what each code means on this model, how sure repair technicians are, and what real repairs showed.

Analyze your panic log How to find the log

First: update iOS

Apple's iOS 18.1 release notes: "fixes an issue where iPhone 16 or iPhone 16 Pro models may unexpectedly restart." An Apple Community 16 Pro showing 2097152 was thought to be that bug. ^{Apple (iOS 18.1)} ^{Apple Community}

What the panic log says

Open the newest panic-full file (Settings → Privacy & Security → Analytics & Improvements → Analytics Data). On an iPhone 16 Pro or 16 Pro Max the important line looks like this (from an iPhone 16 Pro Max on iFixit):

SMC BSC failure with sensor array 0-7 is 0, 3145728, 0, 0, 0, 0, 0

The number that is not zero is the sensor code. Newer iOS versions print it in decimal: 524288 is the same as 0x80000. The table shows both.

Sensor codes on iPhone 16 Pro and 16 Pro Max

Code	Part	Confidence	Sources
`0x300000` 3145728	USB-C charging port flex, or the air-pressure sensor plugged into it	High	iFixit, Repair Wiki, iFixit case
`0x200000` 2097152	USB-C charging port flex, or the air-pressure sensor plugged into it - or the iOS bug fixed in 18.1	Medium	Repair Wiki, Apple Community
`0x100000` 1048576	USB-C charging port flex	Low - one repair shop	iFixit case

What repairs showed

Repair shop reading: Advanced Device Repair on iFixit: 3145728 / 1048576 (0x300000 / 0x100000) is charging port flex damage - for a 16 Pro Max after liquid damage. ^{iFixit case}
After liquid: Repair Wiki suggests checking the Taptic Engine, the air-pressure sensor module for corrosion, and the connector pins. ^{Repair Wiki}
No confirmed repair story yet for this family - if yours gets fixed, post the code and the part on the forum.

Test order

What was repaired last? A screen, battery, charging port or back-glass job is the first suspect - the part fitted, or a cable disturbed during it.
Inspect the flex and its connector under magnification: torn traces, liquid marks, a bent pin.
Test with a known-good original part plugged in. Unplugging the cable does not test it - an unplugged sensor is missing too, so the phone still restarts.
Expect side effects: a replacement front sensor flex loses True Tone and auto-brightness; a battery or back glass that is not paired with Apple's System Configuration shows a parts message.
If a good part does not stop it, the fault is on the logic board (often after liquid damage) - micro-soldering.
Do not restore iOS for a hardware code. An SMC panic happens below iOS; restoring only costs time and, without a backup, your data.

Not the same problem

A purple screen that stays, or purple lines without restarts, is usually the screen itself.
Restarts at random times without SMC PANIC in the log are a different panic - the analyzer reads those too.
The phone will not update or restore (error 4013, 9, 75...): see the restore error lookup.

Sources

Different code, or still restarting after the part swap? Post your panic log on the NoPowerFix repair forum - board-level technicians answer, and every confirmed fix improves these tables.

Ask on the NoPowerFix forum