I have a 2010 HHR. I am unable to lock the doors using the fob but I can unlock the doors using it. I tried both fobs with the same result. Both batteries are new in the fobs. Does the keyless entry receiver need to be reprogrammed or replaced. If it needs to be reprogrammed is it something I can do? Thanks in advance, Bill

 

Unlikey the receiver has anything to do with it. No, you can't program it. If you replace it, it needs to be programmed.

What is the state of the car battery?

 

I haven't had any problem with the car battery. It's about 3 years old.

 

So. Can you hear any noise when you use the fobs lock button ? Or is there nothing, like the fobs are not sending a signal. Lots of auto parts stores have a fob tester that can check if your fobs are working.
If you do hear something trying to lock with the fob it could be a sticking lock solenoid or mechanism.
If none of this applies you could also try a battery disconnect. That will reboot the computers. Not sure if it will help in this case but it's an easy, free attempt.

 

I just realized that both the lock and unlock function do not work but the horn button on the fob does work. I do not hear any noise when trying this. I will try to disconnect the battery tomorrow to see if that works. Thanks.

 

The contacts on the fob wear out; they are replaceable.