SmartKey component ID help
 

Hi All - I was wondering if anyone could help me to identify a component on my SmartKey. This is from a 2007 TCH with remote start (271451-0140). Basically, what happened is my SmartKey stopped working, so I went to replace the battery, but when I opened the case, a component fell out. Needless to say, changing the battery did not do anything!! I would much rather replace the component at $1 than the whole key at $200.
The only markings on the component (looking at a working one) that I can find are "400X" right on the cover. It is a 6 pin component, and it seems that pins 2 and 5 are to ground. In this picture, it is the part that is circled in yellow at the bottom (picture is my working one).

Thanks very much for any assistance.
Cheers
Colin

https://www.camryforums.com/forum/me...artkey-953.jpg