How do I know? Being curios I checked it’s Wikipage. It’s probably correct. Actually it’s closer to AMRAAM AIM-120 in function.
“Guidance: inertial guidance, mid-course update + terminal active radar homing”
It gets its initial targeting info from the A/C and then pops on its radar for the close-in intercept.
The “B” version has a modern AESA radar system.
https://en.wikipedia.org/wiki/AAM-4
OK, Thank You, I confess I was lazy and “Brain dead” due to lack of coffee.