ASM instance startup failing with "terminating the instance due to error 482" in alert log
ASM instance alert log shows below error while starting the ASM instance on second node
Exception [type: SIGSEGV, Address not mapped to object] [ADDR:0x1994] [PC:0x43EFF99, kjbmprlst()+1369] [flags: 0x0, count: 1]
ORA-07445: exception encountered: core dump [kjbmprlst()+1369] [SIGSEGV] [ADDR:0x1994] [PC:0x43EFF99] [Address not mapped to object] 
Use ADRCI or Support Workbench to package the incident.
See Note 411.1 at My Oracle Support for error and packaging details.
Dumping diagnostic data in directory=[cdmp_20180131051633], requested by (instance=2, osid=39620 (LMD0)), summary=[incident=224081].
PMON (ospid: 39577): terminating the instance due to error 482
The cluster_database parameter was changed to FALSE which was resulting in the ASM startup failures
Please run the below from the running cluster node making change to the ASM instance
SQL> alter system set cluster_database=TRUE scope=spfile sid='+ASM2';
This should start your ASM instance now. I hope this resolves your issue.