Sort of. You'll notice that you have quotation marks surrounding the sql
Code:
"SELECT tbl_ProductionItem.ProductionItemPartNumber, tbl_ProductionItem.ProductionItem " & _
"FROM tbl_ProductionItem " & _
"WHERE (((tbl_ProductionItem.ProductionItemType)=[forms]![frm_DailyTested].[cboTestItemType])) " & _
"GROUP BY tbl_ProductionItem.ProductionItemPartNumber, tbl_ProductionItem.ProductionItem ORDER BY tbl_ProductionItem.ProductionIt
When you enclose a string in quotes, that makes it a constant/literal string. So, because this
[forms]![frm_DailyTested].[cboTestItemType]
is inside the quotes, it is considered a literal/constant.
In overview, when vba is processed, it looks for constants/literals, and it looks for expressions to be evaluated. You wanted
[forms]![frm_DailyTested].[cboTestItemType] to be evaluated, and the result placed within the SQL string. But you enclosed it in quotes, so vba/Access did not try to evaluate it(also referred to as rendering the expression).
Bottom line is that SQL did not do what you expected because of the quotes. In fact, [forms]![frm_DailyTested].[cboTestItemType] was ignored from SQL rendering, but might have been interpreted as a missing parameter.
To get the SQL to work the way you intended --get the values of [forms]![frm_DailyTested].[cboTestItemType].
Code:
Me.cboProductionItemPartNumber.RowSource = "SELECT tbl_ProductionItem.ProductionItemPartNumber, tbl_ProductionItem.ProductionItem " & _
"FROM tbl_ProductionItem " & _
"WHERE (((tbl_ProductionItem.ProductionItemType)='" & [forms]![frm_DailyTested].[cboTestItemType])) & "' " & _
"GROUP BY tbl_ProductionItem.ProductionItemPartNumber, tbl_ProductionItem.ProductionItem ORDER BY tbl_ProductionItem.ProductionItem"
Here the [forms]![frm_DailyTested].[cboTestItemType] is now outside of the quotes and will be evaluated/rendered before substituting in the SQL.
In my view you could use Me.cboTestItemType interchangeably with [forms]![frm_DailyTested].[cboTestItemType]. The quotes were the issue as I see things.