Temperature readings freeze on MacBookPro12,1 (13inch, Early 2015)

[kleuter]

SMC sensors temperature readings may freeze sometimes when both conditions are met:

1. Fan is OFF. This model features so-called fan-stop mode when fan is off on idle
2. MacBookPro is NOT connected to AC power

There're multiple ways to "wake" them up:

• connect the laptop to AC power
• spin up the fan manually

There're no solution to the issue I don't believe there will be some. Looks like a bug in SMC firmware related to battery saving.

Demonstration video made by one of our users.

[robni7]

Same here, on a MacBook Air. I have seen it more often, but I cannot remember on what machines / which circumstances. Similarly to your findings, connecting the charger or changing the fan preset makes the readings work again. Rebooting the machine did not help. Changing settings in Energy Saver also did not do anything.

I pasted my log below. Hope it is of some help ;)

tech_info.txt

[kleuter]

Another report from a user running the app on MacBookPro12,1

---

Hi, first thing first thank you for your excellent job on this program, second i have a very annoying issue on my MBP 2015 13", if i am using battery the monitor temperature is stock, isn't constantly updating like always, when i plug in the power cable it start updating temperature as always.
So the program is working fine until i have the power cable connected, otherwise is useless.

Do you know how can i solve this problem? Thank you in advance

Macs Fan Control 1.5.0 [Qt 5.13.1]
MacBookPro12,1
CPU: Intel(R) Core(TM) i5-5287U CPU @ 2.90GHz [2 cores]
GPU: Intel Iris Graphics 6100
macOS 10.15.0

Fans:
Right Side-min{1299}curr{0}max{6199}mode{0}

TempSensors:
TA0P (Ambient) - 34.25, 34.25
TB0T (Battery Max) - 28.1992, 28.1992
TB1T (Battery Sensor 1) - 28.2969, 28.2969
TB2T (Battery Sensor 2) - 27.0977, 27.0977
TBXT () - 28.1992, 28.1992
TC0C (CPU Core 1) - 54, 54
TC0E () - 67.8906, 67.8906
TC0F () - 67.8906, 67.8906
TC0P (CPU Proximity) - 49, 49
TC1C (CPU Core 2) - 55, 55
TCGC (GPU PECI) - 57, 57
TCSA () - 0, 0
TCXC (CPU PECI) - 67.8906, 67.8906
TH0A () - 35.875, 35.875
TH0B () - 34.625, 34.625
TH0C () - 34.625, 34.625
TH0F () - 246, 246
TH0R () - 206.625, 206.625
TH0V () - 34.0547, 34.0547
TH0a () - 35.875, 35.875
TH0b () - 34.625, 34.625
TH0c () - 34.625, 34.625
TH0x () - 34.625, 34.625
THSP () - 129, 129
TM0P (Memory Proximity) - 41.625, 41.625
TMLB () - 129, 129
TPCD (Platform Controller Hub Die) - 50, 50
TW0P () - 129, 129
Th1H (Heatsink Proximity) - 39.75, 39.75
Ts0P (Palm Rest) - 28.75, 28.75
Ts0S () - 129, 129
Ts1P () - 27.6875, 27.6875
Ts1S () - 129, 129
Ts2S () - 32.3359, 32.3359

Disk drives:
APPLE SSD SM0512G - 34

Path: /Applications/Macs Fan Control.app/Contents/MacOS/Macs Fan Control