HouseCallAuto 5/27/2010The P1684 happening at the same time as the P1685 is confusing. I would make sure that the battery terminals are clean and in pristine condition along with the battery itself. I hope this is not the original battery that came with the car.
1. Try clearing the codes and see if any come back.
2. If the wrong key is used to attempt to start the vehicle, but the right key is used within 7 attempts, the car will start but will store this code (P1685). If more than 7 attempts to start the Powertrain Control Module (PCM) will disable the starter and lock the system with this code stored.
3. To unlock the system, insert a known good key, turn the ignition on for 1 hour then turn the key off and back on to reset the system. It can also be reset immediately with a DRB III scan tool.