Solution : https://service.sap.com/sap/support/notes/373097 (SAP Service marketplace login required)
Key words : 
data area r3_<inst, r3<sid>400/r3_<inst, sap system upgrade terminates, r3<sid>400 library, run crtr3inst sid, phase kx_switch phase, additional key words, tcp/ip host, sap system, error message
Related Notes : 
       
| 413107 | Additional Information: Upgrade to SAP Web AS 6.10: iSeries | 
| 390665 | Additional information: Upgrade to 4.6C SR 2 (DB2/400) | 
| 326783 | Additional Info: Upgrade to 4.6C SR1 (DB2/400) | 
| 302480 | Additional Info: Upgrade to 4.6D - DB2/400 | 
| 202169 | Additional Info: Upgrade to 4.6C - DB2/400 | 
| 178823 | Additional Information: Upgrade to 4.6B - DB2/400 | 
| 141661 | Additional Info: Upgrading to 4.5B DB2/400 |