Credit Check is not working in SAP CRM Service order

Dear Experts,

Credit Check is not working in SAP CRM Service order - Message 005 CRM_CREDIT_CHECK 005

Credit check not OK (Automatic credit control) ...

When saving service order (Not: We use SAP CRM billing and not ERP billing)

I had tried  troubleshooting this issue by validating the following :

1) Validate in SMW3FDCUST.

2) Checked Transaction type.

3) Checked Item Category.

4) Validate config in ERP end as well.

5) Checked Middleware setting as well .

I had researched in Wiki and other helpful links however I wasn't able to resolve this issue. 

Please find the attached document with the error message and validation step. Kindly help

Regards,