Dear Experts
credit check does not block sales orders with a value greater than the credit limit.
for example :
for a customer who has a credit limit $ 15,000 I can deliver an sales order of $ 30,000.
the two blocking cases are:
- open items with a value greater than the credit limit
- oldest open items
OVA8 Parameter :

in OVAK : sales ordre type is assisgned to check credit D and credit group 01
I applied all the steps of the note 18613.
Regards.