On AS7816 platforms, the show chassis environment pem command will display incorrect voltage, power, and load values for PEM modules.
user@Device-AS7816 > show chassis environment pem all-members localre: -------------------------------------------------------------------------- FPC 0 PEM 0 status: State Online Airflow Back to Front Temp Sensor 0 OK 21 degrees C / 69 degrees F Temp Sensor 1 OK 33 degrees C / 91 degrees F Temp Sensor 2 OK 26 degrees C / 78 degrees F Fan 0 7096 RPM Fan 1 7096 RPM DC Output Voltage(V) Current(A) Power(W) Load(%) 0 13 0 0 FPC 0 PEM 1 status: State Online Airflow Back to Front Temp Sensor 0 OK 20 degrees C / 68 degrees F Temp Sensor 1 OK 32 degrees C / 89 degrees F Temp Sensor 2 OK 25 degrees C / 77 degrees F Fan 0 7200 RPM Fan 1 7200 RPM DC Output Voltage(V) Current(A) Power(W) Load(%) 0 11 0 0
--> Power voltage, wattage, and load % sensor outputs are not displayed in the CLI command show chassis environment pem for the AS7816 devices
--> The wrong voltage values(garbage values) may also appear for non-qualified PEM models.
user@Device-AS7816> show chassis environment pem all-members localre: -------------------------------------------------------------------------- FPC 0 PEM 0 status: State Online Airflow Back to Front Temp Sensor 0 OK 22 degrees C / 71 degrees F Temp Sensor 1 OK 34 degrees C / 93 degrees F Temp Sensor 2 OK 27 degrees C / 80 degrees F Fan 0 7096 RPM Fan 1 7096 RPM DC Output Voltage(V) Current(A) Power(W) Load(%) -2147483648 13 21474836480 FPC 0 PEM 1 status: State Online Airflow Back to Front Temp Sensor 0 OK 20 degrees C / 68 degrees F Temp Sensor 1 OK 33 degrees C / 91 degrees F Temp Sensor 2 OK 26 degrees C / 78 degrees F Fan 0 7200 RPM Fan 1 7200 RPM DC Output Voltage(V) Current(A) Power(W) Load(%) -2147483648 11 21474836480
-->These issues are seen with the PSU models below and a few other PSU models in the older Junos versions.
Power Supply 0 REV B0 YM-2851FC01R xxxxxxxxxxx ACCTON-850W-AC-AFI Power Supply 1 REV B0 YM-2851FC01R xxxxxxxxxxx ACCTON-850W-AC-AFI
--> The following SNMP alerts will appear due to the 0 value returned from the PEM sensors.
Mar 18 00:50:47 2026 Device-AS7816 chassisd[8103]: %DAEMON-5-CHASSISD_SNMP_TRAP6: SNMP trap generated: Power Supply failed (jnxContentsContainerIndex 2, jnxContentsL1Index 1, jn xContentsL2Index 1, jnxContentsL3Index 0, jnxContentsDescr Power Supply 0 @ 0/0/*, jnxOperatingState 6) Mar 18 00:50:47 2026 Device-AS7816 chassisd[8103]: %DAEMON-5-CHASSISD_SNMP_TRAP6: SNMP trap generated: Power Supply failed (jnxContentsContainerIndex 2, jnxContentsL1Index 1, jn xContentsL2Index 2, jnxContentsL3Index 0, jnxContentsDescr Power Supply 1 @ 0/1/*, jnxOperatingState 6)
--> This is a cosmetic CLI issue and does not affect actual power delivery.->On AS7816 platforms, the "show chassis environment pem" command will display incorrect voltage, power, and load values for certain PSU models.
This is a software issue and is being addressed from version 24.4 onwards.
After the fix, the output looks like
root@d22-26> show chassis environment pem localre: -------------------------------------------------------------------------- FPC 0 PEM 0 status: State Online Airflow Back to Front Temp Sensor 0 OK 30 degrees C / 86 degrees F Temp Sensor 1 OK 38 degrees C / 100 degrees F Temp Sensor 2 OK 33 degrees C / 91 degrees F Fan 0 11888 RPM Fan 1 11888 RPM DC Output Voltage(V) Current(A) Power(W) Load(%) 12 18 216 25 <<<<<<<<<<< pls refer here
2025-10-07 : Article Created2026-06-22: Modified the symptoms to include the issues faced on the PSU model YM-2851FC01R, where the PEM command outputs appear to be incorrect/garbage values due to the non-qualified PSU model. Also, the SNMP alerts