An error code P1684 from an OBDII code reader indicates that the battery had recently been disconnected. This is normal if a new battery was installed but can indicate a connection issue or grounding problem.
What does code reading P1684 means for dodge neon car when you scan the engine
Trouble code P1684 means: The battery has been disconnected within the last 50 starts
Trouble code P1684 means: The battery has been disconnected within the last 50 starts
Trouble code P1684 means: The battery has been disconnected within the last 50 starts
Trouble Code P1684 means:The battery has been disconnected within the last 50 starts
Trouble code P1684 means:The battery has been disconnected within the last 50 starts
Trouble code P1684 means: The battery has been disconnected within the last 50 starts
Trouble code P1684 means: The battery has been disconnected within the last 50 starts
Trouble code P1684 means: The battery has been disconnected within the last 50 starts
Trouble code P1684 means: The battery has been disconnected within the last 50 starts
The P1684 code simply means that the battery has been disconnected within the last 50 starts.
It would be very rare for a P1684 code to turn the light on.