Error when SSIS package is exceuted as scheduled job in SQL server.

I am receiving the below error, when the SSIS package is executed through the scheduled SQL server Job. 

OnError,DEVDSQL03,PDC\devsqlsrvc,Data Flow Task,{AF6398C5-232F-4D33-8FD6-DE1479E17449},{8F885F81-1190-4CE0-BA97-4146EF420B03},3/1/2014 12:00:01 AM,3/1/2014 12:00:01 AM,-1073450910,0x,System.Data.Odbc.OdbcException: ERROR [IM002] [Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified
   at System.Data.Odbc.OdbcConnection.HandleError(OdbcHandle hrHandle, RetCode retcode)
   at System.Data.Odbc.OdbcConnectionHandle..ctor(OdbcConnection connection, OdbcConnectionString constr, OdbcEnvironmentHandle environmentHandle)
   at System.Data.Odbc.OdbcConnectionOpen..ctor(OdbcConnection outerConnection, OdbcConnectionString connectionOptions)
   at System.Data.Odbc.OdbcConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningObject)
   at System.Data.ProviderBase.DbConnectionFactory.CreateNonPooledConnection(DbConnection owningConnection, DbConnectionPoolGroup poolGroup)
   at System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection)
   at System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory)
   at System.Data.Odbc.OdbcConnection.Open()
   at Microsoft.SqlServer.Dts.Runtime.ManagedHelper.GetManagedConnection(String assemblyQualifiedName, String connStr, Object transaction)
   at Microsoft.SqlServer.Dts.Runtime.Wrapper.IDTSConnectionManager100.AcquireConnection(Object pTransaction)
   at Microsoft.SqlServer.Dts.Pipeline.DataReaderSourceAdapter.AcquireConnections(Object transaction)
   at Microsoft.SqlServer.Dts.Pipeline.ManagedComponentHost.HostAcquireConnections(IDTSManagedComponentWrapper100 wrapper, Object transaction)
OnError,DEVDSQL03,PDC\devsqlsrvc,Data Flow Task,{AF6398C5-232F-4D33-8FD6-DE1479E17449},{8F885F81-1190-4CE0-BA97-4146EF420B03},3/1/2014 12:00:01 AM,3/1/2014 12:00:01 AM,-1073450985,0x,component "ADO NET Source" (1) failed validation and returned error code 0x80131937.

I am using ODBC to connect AS400 DB. If i run the job manually, then it is executing without any error. 

Kindly let me know, what I am missing.