You can use the following PowerCLI commands to retrieve and modify the WBEM services status.
To retrieve the status:
$esxcli = $vmHost | Get-EsxCli -V2
$esxcli.system.wbem.get() # To retrieve WBEM services status
To set the status:
$esxcli = $vmHost | Get-EsxCli -V2
$WbemArgs = $esxcli.system.wbem.set.CreateArgs() #Create an Arguments list
$WbemArgs.enable = $true # $true to enable $false to disable
$esxcli.system.wbem.set.Invoke($WbemArgs) # To modify WBEM services status
Alternatively, you can enable WBEM by using ESXCLI.
esxcli system wbem set -e 1