So here is short explanation of how SCCM Client health Check process works.
1. SCCM Agents creates a Scheduled Task called "Configuration Manager Health Evaluation" which runs approximately once a day.
When This task starts it creates and writes information in CcmEvalTask.log in SCCM client logs folder.
2. The task starts C:\WINDOWS\CCM\ccmeval.exe file, which in turn logs information in CcmEval.log file.
3. Output information is sent to Management Point with state messages which by default is done each 15 minutes, you can monitor state message sending to server in StateMessage.log