In common, ASM instance is only access by database instance.
DOC ID:340277.1
Keyword: ORA-12541, ORA-15000, ORA-12528

Solution:
1. Edit listener.ora
Add
SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      #(SERVICE_NAME = +ASM1)
      (ORACLE_HOME = /oracle/product/10.2.0/db_1)
      (SID_NAME = +ASM1)
    )
  )

Check
lsnrctl status
...
  Instance "+ASM1", status UNKNOWN, has 1 handler(s) for this service...
Service "+ASM_XPT" has 1 instance(s).
...

2. Edit tnsnames.ora
ASM1 =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = rac01)(PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = +ASM_XPT)
      (UR=A)
    )
  )

3. set remote_login_passwordfile = exclusive
4. Under $ORACLE_HOME/dbs
orapwd file=orapw+ASM1 password=