Skip to content
MappleCare Community ↗

MappleCare Community

[Solved] How to fix Kernel Panic: Sleep Wake Failure caused by SMC driver assertion timeout during standby on MacBook Pro 14″ M4 Pro

Find answers from other Apple users or start a discussion about your device.

All Forum Rooms

Home › Forums › MacBook, iMac & macOS Lab › [Solved] How to fix Kernel Panic: Sleep Wake Failure caused by SMC driver assertion timeout during standby on MacBook Pro 14″ M4 Pro

Viewing 2 posts - 1 through 2 (of 2 total)
  • Author
    Posts
  • November 14, 2026 at 1:41 pm #5254
    Alex Tanner
    Lead Moderator
    Diagnostic Hardware Specs: MacBook Pro 14″ M4 Pro | OS Version: macOS Sonoma 14.7.1 | Archive Source: Apple Support Community #256642159

    I am running into a persistent issue on my MacBook Pro 14″ M4 Pro running macOS Sonoma 14.7.1.
    Whenever the machine encounters SMC driver assertion timeout during standby, the following diagnostic log appears in Console:

    panic(cpu 8 caller 0xfffffe00efbc): 'Sleep Wake failure in EFI: AppleSMC timed out waiting for kIOPMDriverAssertionReservedBit3'

    I verified that hardware connections are intact and tested across different power sources. What is the verified diagnostic procedure to permanently eliminate this symptom?

    MacBook Pro 14″ M4 Pro | macOS Sonoma 14.7.1
    Apple Discussions Contributor | "Verified Apple Diagnostics Archive"
    November 14, 2026 at 1:41 pm #5255
    Claire Bennett
    Lead Moderator
    Apple Recommended / Verified Community Solution
    This canonical solution was verified and marked as solved in the Apple Support Community archive.

    Adjusting deep standby delay, disabling tcpkeepalive Wi-Fi wakes, and clearing corrupted PowerManagement plists.

    Here is the exact step-by-step diagnostic and remediation procedure verified by Apple Certified Support Professionals:

    1. Audit sleep blockers: pmset -g assertions.
    2. Configure recommended Apple Silicon sleep profile: 
      sudo pmset -a hibernatemode 3
sudo pmset -a standbydelayhigh 86400
sudo pmset -a tcpkeepalive 0
sudo pmset -a womp 0
    3. Flush power cache: sudo rm -f /Library/Preferences/SystemConfiguration/com.apple.PowerManagement.plist && sudo killall -9 powerd.
    4. Perform cold boot power controller sync: Shut down completely, wait 30s, and hold power button until Options appears.

    Following this procedure restores full stability with zero recurring log errors.

    Apple Certified Support Professional (ACSP)
    Cupertino, CA | "Precision Apple Diagnostics"
  • Author
    Posts
Viewing 2 posts - 1 through 2 (of 2 total)
  • You must be logged in to reply to this topic.