[andrew]

When I got out of the car and press the lock button, there was no response at all. After I restarted and stopped the engine, it works again. This only happened twice so far with a long interval. Do you guys think there is a problem with the locking system?

[Blue]

Something wrong somewhere by the sounds of it.

Do you have two keys?

I'd try the other when it happens again.  If it works with the other key, its NOT the locking system. If it doesn't work with either a key...  
I reckon there's a fair chance it's the BCM (I think that's the system that handles the locking).

[Lorian]

Maybe the stop and restart was a co-incidence. My first action would be to put a new battery in the key.

[andrew]

i believe it is not a coincidence. It happened at least twice. The key should be functioning as I can see the light on the key is blinking, but the car just didn't response. As it happened very rarely. I am afraid I can't show it to the dealer about this... Did this happen to anyone? 

[Blue]

The key should be functioning

Yes it should be, but it isn't.  
Do you have another one you can test it with?

Those flashing lights are often triggered at a different point in the electrical switching process, not necessarily at the same time as the transmitter is activated.  Sometimes they are wired to say, "Warning: I am transmitting, or I am about to transmit".

My wife has a remote control for her garage door.  Sometimes the light flashes and the door stays put.
A quick rotation or "fiddle" with the battery, and voila, the door opens.
Don't always trust a remote's lights my friend.

Try another key, if you have one.  Or as Lorian suggested, even try a new battery first.

[andrew]

All right, thanks for the suggestions. I have two remotes. I will try next time. But as I don't bring both keys most of the time and it happens very rarely, it would be difficult to try that. Anyway, thanks for the suggestion. Fortunately, i can fall back on the mechanical key if the electric one fails.

[2i30s]

another member had this problem not that long ago.

[Dazzler]

Did a quick search but could't see the other reference...

[andrew]

another member had this problem not that long ago.

are you referring to this:
https://www.i30ownersclub.com/forum/index.php/topic,617.0.html ?

That is a different problem. His/her key is dead, but mine can still be used after restarting and stopping the engine.

[2i30s]

similar problem,but it was this year.but i cant find it.

I've had a similar problem but probably not related.  Twice it would not lock/unlock the door even when standing right beside the car.  The second time it was obvious that it was some local interferance because the car was parked in the same place as when it happened the first time.

i had the same thing happen i put in two new batterys in both remotes no problems

[Merlot]

I had a problem with the key but it was the car would not start maybe take back to dealer with ALL keys and get them re programed and see what happens

[Blue]

How'd it go with the other Key Andrew??

I had a problem with the key but it was the car would not start maybe take back to dealer with ALL keys and get them re programed and see what happens

We had this problem some time ago.  One remote key would start the car and the other would not.  Both would unlock and lock the car.  Turned out that the chip in the key that communicates with the ignition had failed.  It could not be reprogrammed.  They ordered a new chip (came the next day), fitted same, reprogrammed all three keys (this is required as they all need to match) and everything has been fine.  The third key is the non-remote key.  There is a thread on here somewhere about our issue.

Bob

[andrew]

The problem hasn't happened since last time... So I haven't had the chance to try...

How'd it go with the other Key Andrew??