2747010 - DBQUERY_PRE / DBQUERY_PREERROR - Password for 'SYSTEM' does not work

During EHP upgrade in the below phase getting the following error:

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Current Phase: PREP_INPUT/DBQUERY_PREERROR: Password for 'SYSTEM' does not work, please reenter.
Required System Passwords ERROR: Password for 'SYSTEM' does not work, please reenter. DB-Specific Password
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Log file CHKSYSPWD.LOG contains the following:

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XECUTING /usr/sap/<sid>/SUM/abap/exe/brconnect -u -c -f dbstate -RDB
BR0801I BRCONNECT 7.40 (21)
BR0280I BRCONNECT time stamp: 2017-07-07 08:38:15
BR0262I Enter database user name[/password]:
BR0280I BRCONNECT time stamp: 2017-07-07 08:38:20
BR0301E SQL error -12154 at location db_connect-3, SQL statement:
'CONNECT SYSTEM/********@<sid>'
ORA-12154: TNS:could not resolve the connect identifier specified
BR0310E Connect to database instance <sid> failed
BR0280I BRCONNECT time stamp: 2017-07-07 08:38:20
BR0804I BRCONNECT terminated with errors
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Oracle Database

UPG, Upgrade, EHP, Oracle, Enviroment, Variable, ENV, ORA-12154, System, BRCONNECT, CHKSYSPWD

, KBA , BC-DB-ORA , Oracle , BC-UPG-TLS-TLA , Upgrade tools for ABAP , Problem