Exterior lock button (driver door) rarely works

One of two things is probably going on. Either the 12 volt battery is weak, or the key fob batteries are weak.

You can check the voltage of the 12 volt with the MFD. You can also replace the battery in the keyfob. It takes a CR2032 battery which is available at places that sell batteries. It is a common battery.

The button will only work if the sensor on the car is receiving the signal from the keyfob and if the 12 volt is strong. If the keyfob battery is weak, the sensor has a hard time picking up the signal from the keyfob (reduced range due to weak battery). Also, if the 12 volt is weak, the range is reduced again. If you stand close to the middle of the door, the button will work better. If you stand behind the door in front of the rear door, the button will not work as well.

Check out the battery's and beware of your position when you are pushing the button. The position does make a difference.

Best of luck to you.

2004-9 Prius Keyfob Battery Change <---- Change Keyfob battery.

Weird stuff happening? MPGs dropping? Test The Battery | PriusChat <--- Check 12 volt

 

if it's only the drivers door, it might be the lock mechanism.

 

My 09 was doing the same thing. It got to the point that I had to pull the fob out of my pocket to even unlock which irks me to no end! I replaced the fob battery and everything is back to normal.

 

How about a bad seal at the door button? It's a rubber part, subject to the elements. Small hole letting in moisture, dirt? The other buttons work so maybe just one bad button.

 

Make sure you do not have a iPhone in your pocket. The iPhone often cancels the FOB.

 

Just about any cell phone will interfere with the keyfob. If you carry a phone, you need to keep the fob and phone a good distance apart. Also it helps if the fob is closest to the sensors on the car rather than the phone.