Are you talking the BCM or the PCM ????
The BCM controls the dash gauges primarily, the power door locks and the airbag system. Actually everything that is not engine related. The PCM is the entire vehicle engine computer. Usually, if the dash gauges go out, the van can still run and drive. But, you have no idea what's going on otherwise.
Usually the Chrysler p/n for our vans for the BCM is a TRW 68HC11K4 or 68HC11KA4. The BCM is used by OBD-II feedback. Not sure what the extra "A" difference is with the p/n's. I thought that the BCM was offered in 1998 to 2003. Yours being a 1997 is odd having the older dash design that has no digital feedback and not OBD-II ready.