The culprit can be a fan controll program you may have previously installed.
To my knowledge there are two possible candidates (FanControl & smcFanControl but there may be more that have the same problem).
You can verify if you have them installed and eliminate if needed.
NOTE: this problem is similar but not equal to this one Kernel SMC::smcReadKeyAction error The other one is for another version of OSX.
Procedure to check & eliminate FanControl
Open terminal and search for FanControl:
$ ps -ef | grep -i fan
0 145 1 0 Gio12am ?? 3:58.07 /Library/StartupItems/FanControlDaemon/FanControlDaemon run
This tell you that you really have FanControlDaemon running as pid 145 as PidNumber
To eliminate it :
$ cd /Library/StartupItems/
$ sudo rm -Rf FanControlDaemon/
and then kill the daemon:
$ sudo kill PidNumber
WARNING: if you replicate this procedure replace PidNumber with the PID you get from ps -ef
This eliminate the messages for me.
Procedure to check & eliminate smcFanControl
I also try to run the current version of another fan controll utility called smcFanControl (version is 2.4) and it seem to not work in Maverics (no window) but it produce near the same message in Console:
15/11/13 14:19:35,000 kernel[0]: SMC::smcReadKeyAction ERROR TC0F kSMCBadArgumentError(0x89) fKeyHashTable=0x0xffffff802af9b000
Note that for smcFanControl you got "ERROR TC0F" instead of "ERROR TH0P".
If you have this problem you can try to find and kill the process "smcFanControl" instead.
$ ps -ef | grep -i fan
501 45716 254 0 2:44pm ?? 0:00.38 /Users/dave/Downloads/firefox/smcfancontrol_2_4/smcFanControl.app/Contents/MacOS/smcFanControl
If you find it then kill the rogue process as explained before.
I had the same issue. kextd was consistently using around 14% CPU and tailing of /var/log/system.log showed that it was trying and failing to load com.cisco.kext.acsock over and over again.
I uninstalled the Cisco AnyConnect VPN client using its installer caused the problem to end immediately.
I suspect I had an old version of AnyConnect installed that was from the pre-El Capitan days, and hence it didn't have a valid the signature. Luckily I don't need the AnyConnect client (I had installed it a while back briefly for some troubleshooting) since I use the built-in client.
Best Answer
Are you on OS X 10.7.4 ?
Then an explanation and possible solution might be found here on CNet:
Tackling SMC console errors after OS X 10.7.4 update
"Might", because it didn't work for me - even after uninstalling iStat Menus v2.x, so it must be some other application(s) on my part that is causing this...