DRV2605:Inconsistent diagnostic results

Dear Team,

I am experiencing a problem where DIAG_RESULT and FB_STS in diagnostic mode goes to 1 only once in several times, otherwise DIAG_RESULT goes to 0 (normal).
Even when DIAG_RESULT and FB_STS go to 1, the vibration works fine if requested.

Can you please enlighten us on the correct procedure and conditions for accurate diagnostics.Also, I am wondering how normal/abnormal is determined by this diagnostic function.

Thank you in advance for any help you can provide.

Best regards,

Yoshiki Takahashi