Enable TCP/IP of SQL Server via WMIC for an installer created with Wix Toolset?

I'm looking to enable TCP/IP for SQL Server via CMD.exe using WMIC. I use a CustomAction to set the WixQuietExecCmdLine and another to execute. The command I use is:

WMIC /NAMESPACE:\\root\Microsoft\SqlServer\ComputerManagement14 PATH ServerNetworkProtocol WHERE "ProtocolName='Tcp'" CALL SetEnable

The customaction runs immediately at a certain point in my installer. The installer also requires to be run in Admin mode so permission shouldn't be a problem.

I've set the text ComputerManagement14 to ComputerManagement[SQLVERSION] where SQLVERSION equals the first number in the MSSQLSERVER Version key in RegEdit (example: 14.0.0.0 => 14). That works properly so it's not the problem. I also run this command in CMD and it works. However, when I run the installer, I get the following error: WixQuietExec: ERROR: WixQuietExec: Description = The system cannot find the file specified. WixQuietExec: WixQuietExec: Error 0x80070002: Command line returned an error. WixQuietExec: Error 0x80070002: QuietExec Failed WixQuietExec: Error 0x80070002: Failed in ExecCommon method

Here are the custom actions: `

<CustomAction Id="SetOpenTcpSql"
              Property="WixQuietExecCmdLine"
              Value='"cmd.exe" /c "WMIC &#47;NAMESPACE:\\root\Microsoft\SqlServer\ComputerManagement[SQLVERSION] PATH ServerNetworkProtocol WHERE &quot;ProtocolName=&#39;Tcp&#39;&quot; CALL SetEnable"'/>

and

    <CustomAction Id="CMDOpenTCPExec"
          BinaryKey="WixCA"
          DllEntry="WixQuietExec"
          Execute="immediate"
          Return="check"
          Impersonate="no" />

I've tried changing WMIC to C:\Windows\System32\wbem\wmic.exe to no avail.

Any ideas?

Edit: Here is a snippet of the log file:

MSI (s) (48:6C) [14:54:53:213]: Doing action: SetOpenTcpSql
Action 14:54:53: SetOpenTcpSql. 
Action start 14:54:53: SetOpenTcpSql.
MSI (s) (48:6C) [14:54:53:215]: PROPERTY CHANGE: Adding WixQuietExecCmdLine property. Its value is '"cmd.exe" /c "WMIC /NAMESPACE:\\root\Microsoft\SqlServer\ComputerManagement14 PATH ServerNetworkProtocol WHERE "ProtocolName='Tcp'" CALL SetEnable"'.
Action ended 14:54:53: SetOpenTcpSql. Return value 1.
MSI (s) (48:6C) [14:54:53:215]: Doing action: CMDOpenTCPExec
Action 14:54:53: CMDOpenTCPExec. 
Action start 14:54:53: CMDOpenTCPExec.
MSI (s) (48:28) [14:54:53:221]: Invoking remote custom action. DLL: C:\WINDOWS\Installer\MSI51AC.tmp, Entrypoint: WixQuietExec
MSI (s) (48!04) [14:54:53:232]: PROPERTY CHANGE: Deleting WixQuietExecCmdLine property. Its current value is '"cmd.exe" /c "WMIC /NAMESPACE:\\root\Microsoft\SqlServer\ComputerManagement14 PATH ServerNetworkProtocol WHERE "ProtocolName='Tcp'" CALL SetEnable"'.
WixQuietExec:  ERROR:
WixQuietExec:  
Description = The system cannot find the file specified.
WixQuietExec:  
WixQuietExec:  Error 0x80070002: Command line returned an error.
WixQuietExec:  Error 0x80070002: QuietExec Failed
WixQuietExec:  Error 0x80070002: Failed in ExecCommon method
CustomAction CMDOpenTCPExec returned actual error code 1603 but will be translated to success due to continue marking
Action ended 14:54:53: CMDOpenTCPExec. Return value 1.

Note that it says it continues because I use Return="ignore" instead of Return="check" for the CustomAction.

Edit 2: By the way, I've also tried executing normally:

<CustomAction Id="CMDOpenTCPExec" Directory="INSTALLFOLDER" Execute="immediate" Impersonate="no" ExeCommand="[SystemFolder]cmd.exe /c "WMIC &#47;NAMESPACE:\\root\Microsoft\SqlServer\ComputerManagement[SQLVERSION] PATH ServerNetworkProtocol WHERE &quot;ProtocolName=&#39;Tcp&#39;&quot; CALL SetEnable" />