The numbers in which I'm most interested

  • -2
  • 0
  • 3
  • 5

… I might add to that shortlist.

What do those numbers mean; where might we find authoritative explanations?

Somewhere in Apple open source, maybe?


There's a suggested answer for -60, a question about -81, a debatable suggested answer for -108, discussion of -128, -72, -62, -30, -2, 0, 3 … and so on, but unless I'm missing something:

  • nothing like an Apple-provided list of explanations of the commonly seen numbers.


Three messages recently sent by kernel on a MacBookPro5,2:

2014-03-31 09:04:49.000 kernel[0]: Previous Shutdown Cause: 5
2014-03-31 11:01:24.000 kernel[0]: Previous Sleep Cause: 5
2014-03-31 14:47:00.000 kernel[0]: |Previous Shutdown Cause: -60

Possibly relevant to some cause numbers

Error codes in http://www.opensource.apple.com/source/CarbonHeaders/CarbonHeaders-18.1/MacErrors.h

  • that's in Apple open source for Mac OS X 10.6.2 but not in open source for Mac OS X 10.6.3
  • the source code for 10.6.2 is almost identical to what's installed under MacOSX10.8.sdk
  • it may be sensible to treat some of those error codes as deprecated.

6 Answers 6


The precise meaning of the codes is not publicly documented, although according to @grgarside's website for Shutdown Causes, the causes for the ones listed in the question are:

For a full up-to-date list, see Shutdown Causes.

See also: List Of Mac OS X Error Codes.

Here on Ask Different, there have been a number of questions about shutdown causes:

If you've got negative numbers very often, Apple is more keen to get your Mac to the repair, as it usually indicates problem with your hardware.

General suggestions in case of further problems:


So the kbase articles on System Error codes date back to the days of PowerPC processors, which apparently needed a lot more bits to report all of the potential hardware errors that could cause a shutdown. Starting with the advent of Intel boards, all shutdowns are tagged with an 8-bit code, if the normal software shutdown flags are not recorded. A positive code indicates a software or HID initiated shutdown, while a negative code (in the range of -1 to -127) indicates hardware-related Intel SMC-initiated shutdown. A -128 shutdown code indicates a hardware-related shutdown of unknown cause.

The 0 shutdown code resides in a liminal space between the hardware and the user; it signifies a sudden loss of power which can either be caused by a hardware failure or user action (if you want to demonstrate this for yourself, try popping the battery out of an old MacBook or MacBook Pro while it's on and unplugged, or pulling the power cord out of an iMac while it's running, then rebooting the computer and checking Console.app. A 0 Sleep Cause results when a MacBook/Pro/Air puts itself into SafeSleep using the last bit of reserve battery power before full system shutdown in order to preserve the contents of RAM in the


file. Unless you happen to connect your MagSafe adapter immediately after the computer goes to sleep, this code is pretty well guaranteed to be followed a 0 Shutdown Cause in the system.log.

Some of the hardware shutdown codes are unique to specific models of computer depending on their configuration because they refer to a specific sensor or device that exists only in that model– when I worked for Apple we were told that Intel was responsible for assigning the codes and wasn't particularly free with the information sharing on that count, even with Apple Engineering. So we pretty much had to figure out the obscure ones on our own.

Previous Shutdown Cause 5 and 3 are holdovers from the PowerPC days- because they're initiated by the user, the OS is still responsible for reporting them.

Code 5 is a clean, user initiated software shutdown, e.g. by selecting Shut Down from the  menu, or pressing the power button and selecting Shut Down in the pop-up window, or holding down controloptioncommandeject, or typing

sudo halt

at the command prompt. Similarly, a Previous Sleep Cause of 5 indicates any clean user-initiated sleep, from the  menu or a hot corner or the command line or closing the lid and triggering the hall-effect sensor in the top case of a MacBook/Pro/Air.

Code 3 is a "dirty" Shutdown, which can be caused by any user-initiated Reboot of the computer, or by forcing a hardware computer halt by holding down the power button for 5+ seconds.

  • Thanks! So 3 would result from a forced restart (Command–Control–Power button), yes? Commented Dec 14, 2015 at 19:40
  • 1
    There is also a code "1" for restart using menu. Commented Nov 29, 2019 at 13:59

Apple Internal Document on Shut Down codes

This is the codes we used to use when I worked there


I filed a bug report with Apple about the cryptic numbers, and eventually got this response:

Engineering has determined that this issue behaves as intended based on the following information:

If your looking for more sleep/wake related info, "pmset -g log" is the place to go, not the system.log everything behaves correctly.

If you have questions regarding this resolution, please update your bug report with that information.

We are now closing this bug report.

Please be sure to regularly check new Apple releases for any updates that might affect this issue.

In summary: they recommend using the command pmset -g log to diagnose sleep issues rather than looking at the system log.


I could help you out with code 0 which means there was no problem, and it was successfully.

I have found an old list, from back in 1998 before OS X. It might help you in the right direction even though it isn't quite the exact answer you're looking for.

If an errorcode is deprecated it won't be replaced by a new cause, because that would only make it much more difficult to keep track of these numbers used in OS X and prior.

  • 1
    Thanks. The most recent edition of that old list is probably Macintosh: System Error Codes Explained, archived by Apple. Commented Apr 5, 2014 at 11:04
  • @GrahamPerrin you could make your comment in to a answer!
    – Ruskes
    Commented Apr 5, 2014 at 11:59
  • 1
    I would doubt McOS <=9 info is relevant to anything here - the kernel etc was running as NeXT from 1989 and I think would use these values rather than changing to the OS <=9
    – mmmmmm
    Commented Jul 9, 2015 at 21:48
  • Those are unrelated — they're classic OS (now Carbon) error codes. They're used for application-level API error codes; even in the classic OS they weren't used to identify system crashes.
    – Jens Alfke
    Commented Feb 27, 2016 at 1:37
  • I am pretty sure the shutdown cause is NOT equivalent as System error codes Commented Nov 29, 2019 at 14:02

Hope it will helps someone.

MBP 2008

  • 3 Normal behavior... power button was pressed for more than four seconds to force shutdown.
  • -5 Normal behavior... regular shutdown
  • -60 Try charging battery.
  • -70 Replace top case.
  • -72 replace heatsink sensor/reapply thermal paste/replace heatsink (it was mine problem)
  • -74 swap battery for KGB battery - replace battery
  • -78 Charger circuit on logic board...try swapping for KGB left I/O board... replace if necessary/replace logic board
  • -82 Test thermal sensor JST connectors for improper seating or damage. Replace thermal sensor(s). See Thermal Sensor take apart section

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