MacBook Air fan running more after Sierra update

reset your SMC

Reset the System Management Controller (SMC) on your Mac - Apple Support

I had this issue immediately after I installed Sierra on my MacBook Air. First I tried resetting the SMC and the PRAM. This did not stop the fans from constantly running. I then used Activity Monitor to see what was possibly overtaxing my system. I saw that the 'secd' process was consistently sucking up over 90% of my CPU usage. Others however said that this is normal after an OS upgrade and should drop back down after the computer finishes its initial photo and file scanning. I therefore let my MBA run plugged in nonstop for 36 hours straight and the fans just kept running while the 'secd' process continued to drain at >90% CPU usage. I also looked closer at the Activity Monitor and saw that tasks like photo analysis had their own processes separate from 'secd'. So I digged more into what the heck 'secd' was really doing with so much of the CPU resources. Long story short, I found that there is some glitch in Sierra that causes the macOS to get stuck on a process involving the Keychain and iCloud.

This is what I did to address this Keychain/iCloud issue that was leading to 'secd' overtaxing the CPU and triggering the fans to always be on:

-In Activity Monitor, I used Force Quit to kill the process that involved the Keychain

-In Activity Monitor, I then Force Quit the process that involved iCloud

-In Activity Monitor, I finally Force Quit the 'secd' process. (I found that I could not simply Force Quit 'secd' without first killing the Keychain & iCloud processes first)

-After all that, I restarted the computer and the fans were finally off! I opened up Activity Monitor and saw that 'secd' was no longer hogging up CPU usage. Processes like photoanalysis were still running in the background at 40-50% CPU usage with no unwanted triggering of the system's fans. iCloud syncing and my Keychain were also functioning just fine.

I finally am able to use Sierra without my fans blazing out of control. Took me awhile to get this sorted out. Hope this helps save you some headaches and time until Apple is able to realize that there is this Sierra software glitch they need to address.

Thank you so much for this suggestion and all the other help I constantly receive from the Community.

In my case I discovered that "Installer" was hogging a huge percentage of the CPU. I ejected it and it has fixed the problem.

Hey DrJus.

I tried following your instructions on my MacBook Air as well, and after 5 attempts, 'secd' comes back and continues to run at 70-80% CPU usage. Can something else be holding it hostage and forcing it to continue running?

thanks so much! i force stopped the keychain part and everything was fine! sure hope Apple fixes this!!

If your 'secd' keeps coming back with large amounts of CPU usage, then some other process is likely holding it hostage. For me, you already know it was the iCloud keychain. Before I pinpointed that it was the keychain process that needed to be killed first, it would just keep reactivating secd no matter how many times I tried to force quit secd alone. I think you will have to use Activity Monitor to see what processes are active. Kill off one process followed by killing off secd to see if this releases secd from reactivating. It will take some trial and error but I think you will eventually find your locked up process. I wish I could be more helpful. Apple really needs to work out this Sierra glitch and roll up an update to just fix this.

Thank you So Much for this help,

i have A question, after i restart my mac The 'secd' still come back in activity monitor?

so i must start over again, it's alright? Or only me?

Thanks

If you restart and see 'secd' running in the activity monitor, this is normal as long as it is not constantly hogging up >90% of the CPU. 'secd' is a normal process that should pretty much be always running (typically up to 70% CPU usage for brief periods depending on the task it is doing). But in the case of the fans always being on after installation of Sierra, 'secd' was being constantly overtaxed with extreme CPU usage do to a process lock up. If you were like me where the process involved the Keychain and iCloud, killing off this locked up process successfully should have allowed 'secd' to return back to its normal patterns of CPU usage.

Thanks, got the Very same problem when upgrading directly from yosemite to Sierra on a macbook pro.. laptop going bonkers because secd process is taking 100% cpu and all the ram for itsellf..its a memory leakage ..if you kill the process on its own just comes back again...to stop this you have to kill all the related keychain and icloud processes First...like DrJus says... then follow this instructions :

Open a Finder window
Click "Go" on the menubar
Hold down the Option key and the Library folder will appear
Click on the Library folder and look for the Keychain folder within the Finder window
Drag the folder into the trash but do not empty the trash.
Restart your computer
Keychain will be reseted; there is still no need to empty the trash yet

And then: with spotlight open terminal and enter

launchctl stop com.apple.secd

killall secd
launchctl start com.apple.secd

Had to try this several times until it worked..at least that seems for now ...fingers crossed..

This and the bloody weather widget on dashboard not working its driving me nuts..Man, Apple Quality control goes downhill every release..

its my fault breaking the rule of never install a new Os until the second or third revision.. sigh..

on yosemite all was working like a charm.

Thank you! This fixed my problem!

Glad to help you all out!

Problem same. But started only after doing the 10.12.1 additional upgrade. Computer got hung up on Local Keychain issue. Since then computer heating up considerably and battery draining in about 2 hours. Before could charge MBA twice maybe three times a week. Update done 2.5 days ago. Getting tired of this now as first time in over 2 years with the MBA that I have had any problems at all.

Hope the following helps anyone with heating up issue: Apple tech told me yesterday that after upgrading to Sierra (in my case to 10.12.1) the computer would need to work hard over a couple or more days indexing all my documents and photos, amongst other things on the computer. Up to early this morning it was still heating up and running down my battery. HOWEVER, in the last couple of hours - even during the time I have been recording a complicated 'voice-over' using GarageBand, the computer has stopped heating up and battery consumption is back to normal.

Kudos to Matthew at Apple Chat who said that it would revert to normal operation in due course. It has done. And I am happy about it.

Thank you so much!! My computer immediately hushed after this and the spinning wheel of death hasn't made another appearance yet.