diff --git a/fsmPev.py b/fsmPev.py
index 74d0e40..332a417 100644
--- a/fsmPev.py
+++ b/fsmPev.py
@@ -286,7 +286,10 @@ class fsmPev():
                     self.sessionId = strSessionId
                 except:
                     self.addToTrace("ERROR: Could not decode the sessionID")
-                if (strResponseCode!="OK_NewSessionEstablished"):
+                if ((strResponseCode!="OK_NewSessionEstablished") and (strResponseCode!="OK")):
+                    # According to the standard, the only valid response code is OK_NewSessionEstablished.
+                    # But the ABB chargers use "OK", so we need to accept this, too. Discussed
+                    # here: https://openinverter.org/forum/viewtopic.php?p=58399#p58399
                     self.addToTrace("Wrong response code. Aborting.")
                     self.enterState(stateUnrecoverableError)
                     return