Support Support Downloads Knowledge Base Case Manager My Juniper Community

Knowledge Base

Search our Knowledge Base sites to find answers to your questions.

Ask All Knowledge Base Sites All Knowledge Base Sites JunosE Defect (KA)Knowledge BaseSecurity AdvisoriesTechnical BulletinsTechnotes Sign in to display secure content and recently viewed articles

[ACX] Toggling I2C error for PEM and FAN



Article ID: KB34051 KB Last Updated: 21 Jun 2019Version: 1.0

This article explains why the chassis on ACX6360-OX may raise intermittent I2C Access Error alarms against FRUs (field replaceable units), including Fan and PEM, and whether any action must be taken to clear the alarms.



The following alarms will toggle and clear autonomously:

Feb 26 00:50:13  [nodename] alarmd[7113]: Alarm set: FAN color=RED, class=CHASSIS, reason=Fan Tray 3 I2C Access Error
Feb 26 00:50:13  [nodename] alarmd[7113]: Alarm cleared: FAN color=RED, class=CHASSIS, reason=Fan Tray 3 I2C Access Error
Feb 27 18:46:54  [nodename] craftd[7114]:  Major alarm set, PEM 1 I2C Failure
Feb 27 18:46:54  [nodename] alarmd[7113]: Alarm cleared: PS SFXPC color=RED, class=CHASSIS, reason=PEM 1 I2C Failure‚Äč



The firmware version query mechanism was revised in Junos OS release 18.3R1-S1 and later to avoid I2C collisions, which eliminates the conflict and alarms.

Meanwhile, no action is required because the condition is cleared autonomously and does not affect any service.


Comment on this article > Affected Products Browse the Knowledge Base for more articles related to these product categories. Select a category to begin.

Getting Up and Running with Junos

Getting Up and Running with Junos Security Alerts and Vulnerabilities Product Alerts and Software Release Notices Problem Report (PR) Search Tool EOL Notices and Bulletins JTAC User Guide Customer Care User Guide Pathfinder SRX High Availability Configurator SRX VPN Configurator Training Courses and Videos End User Licence Agreement Global Search