Smart Array P420 in Slot 2 CACHE STATUS PROBLEM DETECTED: The cache on this controller has a problem

Hi there,

We have ProLiant DL380p Gen8 with Cache Module error code 351.

351 Smart Array P420 in Slot 2 CACHE STATUS PROBLEM DETECTED: The cache on this controller has a problem. To prevent data loss, configuration changes to this controller are not allowed. Please replace the cache to be able to continue to configure this controller

Do any one know spare part of p420 cache module to be replaced? 

Thanks

Roy