How to get XBEE S2C to pair pins

I have successfully performed bi-directional pin pairing using the older S1 series 802.15.4 modules. I have tried to do the same with newer S2C modules (XB24CAPIT-001)but I’m running into problems. I can successfully activate the output pins via API packets but can get them to activate otherwise. Am I missing something?

You are using the Zigbee firmware instead of the 802.15.4 firmware. Only the 802.15.4 does IO line passing.

Actually By default, I was using 802.15.4. Turns out one of the radios seemed to be faulty. Switched out with a new one and it now works. Thanks though!