My key suddenly stopped working. I replaced the battery and can see the little red light flashing. I can't unlock or lock the door. Car beep when i turn off the car and open the door. It flashes the lock red symbol. I can turn on and turn off the car. There is no " no key detected warning"
Sounds like the key is working just fine except for locking/unlocking the door. Try disconnecting the negative terminal on the 12V battery for a few minutes, reconnect, and try it again.
key fob buttons were worth a try! the 12v battery is in the back hatch. Open hatch and on the side there is compartment lid to open. Use an adjustable wrench to loosen the clamp on the battery, put a bag or something around that detached cable so it does not touch/connect back to battery. wait 5 mins reconnect the cable to the post and tighten. Do not let cable touch anything and if you have metal wrench, do not short out by touching both posts.
