Question

What do the engine codes P1684 and P1685 mean for my 2000 Dodge Neon? the vehicle won't start

Answer 1

P1684 Status PCM memeory has been cleared since the last 50 ignition cycle

P1685 Invalid skim key

P1684 just ignore, what happens the CK ENG LT was recently cleared, What is causing the no start is a invalid key, P1685 is invalid key, use another key.

Answer 2

P1684 DODGE Code - Battery Power To Module Disconnected
Read more: https://www.autocodes.com/p1684_dodge.html

P1685 DODGE Code - Invalid SKIM Key
Read more: https://www.autocodes.com/p1685_dodge.html