How to update “Display-only” material master fields (Gross/Net Weight) via MM17 or IDoc in S/4HANA?

[amineaitsi]

Hello SAP Community,

I am working in S/4HANA and I have a scenario with material master fields MARA-BRGEW (Gross Weight) and MARA-NTGEW (Net Weight).

• In MM02, these fields are set to Display only via field selection (OMS9/OMS2).

• I want to update these fields via MM17 (mass maintenance) or MATMAS IDoc.

• Currently, SAP blocks the change and returns MG140: “Field not ready for input”.

I understand that SAP marks these fields as non-dialog in the backend, so the “Display only” status does not allow updates through direct input or IDocs.

My question:
Is there a standard / S/4HANA-supported way to update these display-only fields programmatically (via IDoc, MM17, or API), without changing the MM02 screen status?

[Lakshmipathi]

No, SAP does not support updating display-only fields like MARA-BRGEW and MARA-NTGEW via MM17 or MATMAS IDoc unless their field selection status is changed to allow input. This restriction applies even in S/4HANA.

Why you can’t update display-only fields via MM17 or IDoc is because, Field Selection Controls in OMS9/OMS2 settings define whether a field is optional, mandatory, or display-only across transactions like MM02, MM17, and IDoc processing. SAP treats display-only fields as non-dialog, meaning they are excluded from update logic—even if technically present in the IDoc or MM17 structure. The error message MG140 confirms that the field is locked for input and cannot be updated programmatically unless its status is changed.

Some workarounds are

Use transaction OMS9 to change the field selection group for BRGEW and NTGEW to “optional” or “required.” This allows MM17 or MATMAS IDoc to update the fields. After the update, revert the field status to “display” if needed for business control.

You can use BAPI_MATERIAL_SAVEDATA to update these fields, but only if field selection allows input. Include the values in the UNITSOFMEASURE structure and ensure the field selection permits updates.