Model A1502 / 2.4, 2.6, or 2.8 GHz dual-core Intel processor / Released October 2013

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Fan at full speed and kernel_task at +300%

This MacBook Pro's (late 2013, model 11,1) fan run at full speed and the kernel_task is at +300% with +100 threads. Temperature Gauge Pro shows normal temperatures.

Apple Diagnostics gives errors PFM006 and PPN001, and after some research this seems to be a thermal sensor error.

Apple Service Diagnostics (ASD 3S162) returns the following errors:

EFI:

  • Sensor - Temperature (TSoP) -- Palm Rest (test 1) - Sensor Reads Within Operating Range - Check to ensure that sensors read within operating range. ERROR - Sensor is reading below the limit

OS (read that this spits out jibberish?):

  • ERROR -- 1 [The SMC reports an error on one or more critical sensors]
  • ERROR --13005 [The SMC can not read this sensor]
  • ERROR -- 8 [Plimit not as expected]
  • ERROR -- 12012 [Child process exited due to signal. Usually a crash!]

What I have done so far:

  • Reset SMC. No luck there.
  • $ sudo mv /System/Library/Extensions/IOPlatformPluginFamily.kext/ ~. This lowered kernel_task to 2-100% and the computer feels somewhat snappier, but the fan still runs at full speed.

The previous owner installed Macs Fan Control to lower the fan speed. But of course the computer was still slow due to the kernel_task process.

According to someone (and our saviour Loius) cleaning the trackpad cable and thermal sensors solved his problem.

Searching for the TSoP error seems to suggest disconnecting the iSight camera. However the iSight camera works fine.

The ALS seems to not work since the screen and keyboard brightness does not change when blocking the ALS. But the ASD OS interactive ALS test passes.

I plan to open the computer and clean the fan with compressed air, and also try to clean the trackpad cable, thermal sensors and iSight cable. Should be possible without removing the battery?

What is my best course of action here? I have never repaired a MacBook, so I'm a bit worried to mess it up.

I guess I could just manually set the fan speed since the kernel_task process is "solved", but it seems like a secondary solution...

Answered! View the answer I have this problem too

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Hi,

I have the same problem. How did you clean the stuff? With ethanol?

And what exactly did you clean?

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I use distilled water (not tap!) were I go lightly over the areas where I see corrosion with a soft tooth brush. I then use 85% or better isopropyl alcohol over the same areas to help in removing the water and speed up drying. I then leave the parts out on a sunny window sill to gain the warmth of the sun to finish drying for a good day.

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Hey! I used 99.5% isopropyl (dries in seconds) and cleaned pretty much every connector with a toothbrush. But I'm positive that the PCB on the trackpad was the real issue. So remove the batteries and the trackpad, mine had corrosion on the backside. Good luck!

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@taeb - Water is a better solvent with sugary spills than isopropyl alcohol alone. You need to be the judge what to use as only you can see what needs cleaning.

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It is directly under the trackpad? So I have to remove the batterie?

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Chosen Solution

Remove the logic board and check the bottom for liquid damage, especially around the SMC and top right, where the CPU thermal sensors are.

Check the trackpad cable pins and trackpad board for liquid damage or burnt pins. If there are either, you will need to replace these (and remove the battery to do so).

Regarding ALS not working, chances are the screen has been replaced before with a bad refurb. With the screens on eBay, a lot have this issue, so you have to push and cover the ALS for it to work sometimes (light shines through from the screen to the sensor, preventing it from reading dark enough to light the keyboard). No way to resolve this unless you want to remove the LCD panel and put a bit of foam between the ALS and backlight sheets, or replace the whole assembly.

Most likely it is the trackpad or liquid damage around the SMC.

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Thanks for your reply. I managed to find some liquid damage to the touchpad, but after a thorough cleaning it seems to be fixed! The PFM006 and PPN001 are gone in AD, however ASD EFI gives me a new error:

Sensor - Current (IPBR) -- Charger (BMON)

ERROR Sensor is reading above the high limit - TEST FAILED

Some kind of battery/charger error? It seems to charge as it should. Temperatures, fan speed and performance are normal.

edit. Also the ALS works now :)

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Usually that error is caused by 3rd party batteries, some liquid damage on the battery PCB or an issue with the charging circuit on the logic board. Check the battery PCB and clean if necessary, but otherwise leave it as is.

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Since the battery is originaI I went ahead and cleaned the battery PCB. Now ASD EFI returns "passed"! Thanks again for your support, this was way easier than I had imagined :). I pretty much assumed that liquid damage often equaled permanent damage.

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@taeb how you removed the batteries to clead the touchpad?

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Ignore the "how"

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taeb will be eternally grateful.
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