SRS Airbag System Malfunction light

After installing new head unit in my tundra, the SRS Airbag System Malfunction light popped on. Wondering what could cause this. I disconnected the battery when installing the unit

UPDATE/RESOLVED: After plugging the climate control back in, the light went away. I guess it makes sense since the airbag light on that panel

 

Dude thank you so much for posting this. I was absolutely pulling my hair out after installing a radio. I figured I had hit something in the knee airbag, etc. I tried the negative terminal thing, etc. Not luck. I had even purchased a OBD scan tool to reset the light. Turns out it was just that I didn't have that panel in yet (I was waiting until I was sure the radio was all working correctly). Put the panel in, boom, the light is gone. Thank you!