iPhone 14 — sensor array 0x40000000: Battery

Medium confidenceVerified sourceSMC: silent sensor

On the iPhone 14, 0x40000000 means: Battery (TB0T / TB0V sensors: temperature and voltage not reported).

What does this code mean?

SMC “BSC failure” panic: the system management controller (built into the SoC) periodically waits for a response from each mandatory sensor and forces a restart, roughly every 3 minutes, as long as a sensor stays silent. Here the mapping comes from the sensor names, not from the code: TB0T is the SMC key for battery temperature (TB0V, the voltage), and the iPhone 14 Pro Max (iFixit 936588) and 15 Pro (iFixit 943079, battery replaced = fixed) cases that name TB0T link the panic to the battery. The code 1073741824 (0x40000000), which appeared with recent iOS versions, does not appear in any public source; neither does bit 0x10 in the next word. For the iPhone 14 and 14 Plus, the iFixit table gives 0x500000 as battery, a disputed mapping (DFRWS: port + coil), and 0x400000 = wireless coil.

Which part to test first?

Check whether the battery percentage is stuck (0–1%) or missing, inspect the battery connector and its flex (pins, corrosion), test with a known-good genuine Apple battery (+ System Configuration to avoid the warning), then measure the battery data lines on the logic board in diode mode.

The same code on other models

Field cases

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Sources