DTC 6-4: Backup Battery Connection Error: Description

After the engine switch is turned on (IG) and 10 seconds or more have passed, if the telephone ECU assembly does not recognize the mayday battery (backup battery), this DTC is stored.

HINT:

This DTC is only a historic DTC.

DTC Code	DTC Detection Condition	Trouble Area
6-4	Communication or the communication line is abnormal between the telephone ECU assembly and mayday battery.	Telephone ECU assembly Mayday battery (backup battery) Harness or connector