Sub Défauts()
Dim c As Range, x
With Sheets("Défauts")
.Range(.Cells(2, 1), .Cells(Rows.Count, 2).End(3)).Name = "DATDEF"
End With
Application.ScreenUpdating = False
For Each c In Sheets("Audit S0").Range("C2:C5000")
If Not IsEmpty(c) Then
x = VBA.Left(c.Text, 3) * 1
If IsError(Application.VLookup(x, [DATDEF], 2, 0)) Then
c.Value = c.Value
Else
c.Value = Application.VLookup(x, [DATDEF], 2, 0)
End If
End If
Next
End Sub