Hardisc error

I get this error on our Sun Server (Sun Microsystems sun4u 5-slot Sun Enterprise E3500). Suspected to be hardisk error, can someone explain to me the severity of the problem? Do we need to call sun engineer on this or change hardisc?..thanks.

Dec 11 22:14:26 oracle unix: WARNING: /sbus@2,0/QLGC,isp@2,10000/sd@5,4 (sd181):^M^M

Dec 11 22:14:26 oracle unix: Error for Command: readError Level: Fatal

Dec 11 22:14:26 oracle unix: Requested Block: 1696 Error Block: 1696^M

Dec 11 22:14:26 oracle unix: Vendor: SymbiosSerial Number: ;>d ^M

Dec 11 22:14:26 oracle unix: Sense Key: Hardware Error^M

Dec 11 22:14:26 oracle unix: ASC: 0x45 (select or reselect failure), ASCQ: 0x0, FRU: 0x22^M

Dec 11 22:14:26 oracle unix: WARNING: The Array driver is returning an Errored I/O, with errno 5, on Module 1, Lun 4, sector 1696^M

[869 byte] By [bronze-starDukes] at [2007-11-26 12:15:13]