Apple Hardware Test Error

Discussion in 'MacBook Pro' started by Cynic, May 8, 2012.

  1. Cynic, May 8, 2012
    Last edited: May 8, 2012

    Cynic macrumors newbie

    Apr 4, 2012
    Hi all

    Anyone have any idea what the following error message relates to?


    From what I've seen already this relates to a sensor error. But I am not sure which one! Is there a way of finding out? I cannot get this repaired because there has been water damage.

    It's a late 2011 MBP. Works perfectly apart from the fact it does not scale CPU above 800mhz under any circumstance.

    Temperature sensors are all okay.

    Thanks in advance!
  2. Dangerous Theory macrumors 68000

    Jul 28, 2011
    Does the battery work? MBPs under clock when the the only power draw is from the AC I believe?
  3. astrorider macrumors 6502

    Sep 25, 2008
    Are you running off battery when running the test? I thought I remember a false positive I'd get on my machine if I ran the test without being plugged in. Sorry if this is totally off base, just thought I'd throw it out there in case it helps.
  4. Cynic thread starter macrumors newbie

    Apr 4, 2012
    Yes - the battery works fine - I ran the test when on A/C.

    Bit of a strange one!

    I have also noticed in os X the kernel process uses all the CPU. But this does not happen in safe mode or in windows?
  5. boilermaker80 macrumors newbie

    Jul 10, 2016
    Regarding Apple Hardware Test fault number: 4sns/1/40000000:ibor-9.166. CPU usage above 300% by kernel task, I recently had the same issue. The 4SNS portion of the fault indicates problem with a system sensor. The ibor portion of the fault (first letter "i" indicates current problem and second letter "b" indicates problem with the battery. I installed istat pro to troubleshoot. I left the bottom cover unattached and found that when I disconnected the internal battery the system (while the Macbook was on) istat pro reported CPU usage dropped from ~95% (kernal panic) to around 30%. Note that I did not have any errors with the battery and the battery charged fine (it had 373 cycles). The Macbook performance was significantly improved (boot time and responsiveness in OSX). In istat pro, there were three temperature sensors which read open when I disconnect the internal battery. I deduced that there was an issue with one of the three sensors. I did not try a different battery to determine if that would resolve the issue.

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