ASM Password is not working for SYSASM privilege but the same pass working for SYSDBA privilege

Hi,

ASM Password is not working for SYSASM privilege but with the same password I can login with SYSDBA privilege.

[grid@DC-DB-01 ~]$ sqlplus /nolog

SQL*Plus: Release 11.2.0.1.0 Production on Wed Oct 22 15:31:09 2014

Copyright (c) 1982, 2009, Oracle.  All rights reserved.

SQL> conn sys as sysdba

Enter password:

Connected.

[grid@DC-DB-01 ~]$ sqlplus /nolog

SQL*Plus: Release 11.2.0.1.0 Production on Wed Oct 22 15:31:47 2014

Copyright (c) 1982, 2009, Oracle.  All rights reserved.

SQL> conn sys as sysasm

Enter password:

ERROR:

ORA-01031: insufficient privileges

SQL> select * from v$pwfile_users;

USERNAME                       SYSDB SYSOP SYSAS

------------------------------              ----- ----- -----

SYS                                   TRUE  TRUE  TRUE

ASMSNMP                         TRUE  FALSE FALSE

1638586.1 document says I can use ALTER USER .. to change password. Does it change password for sysasm privilege too ?