My keyless entry suddenly stopped working a few days ago. All it does when i press the lock/unlock button on the key is lock the doors without activating the alarm.. if i press it again to unlock, nothing happens.

I replaced the battery in the key to no avail. I imagine the receiver in the car has gone faulty? Anyone with any ideas?

 

You can try disconnecting the car's battery and reconnecting it, sometimes a simple ECU reset will fix the strangest problems.

 

What year is the vehicle? I ask this because mine is a 92' es300 and I might be having the same problem. I don't even know if the car has an actual alarm sound that goes off or lights that go off to indicate the doors have been locked/unlocked. I never got a owners manual with mine.

 

95' I'll try resetting the battery later today. I don't know about the 92, but my 95 makes a BEEP when it's locked or unlocked with the keyless. Also there is a red alarm light on the dash by the mirror adjust buttons, which becomes lit when it's locked, except now it's not working.

 

Resetting the battery did not help. The keyless entry still can only lock the doors without activating the alarm, and that's all it can do.

 

I'm not sure if the ES has C-Best settings like the RX, but if it does then the dealer can adjust the settings so that it activates the alarm when you press lock on the remote key.