DIC Oil Pressure

Have a 2000 Buick Lesabre with DIC (Driver Information Center?) readout. Problem is with oil pressure indicator. In the past DIC registered oil pressure as normal with 60psi. Oil pressure varied with acceleration of vehicle. Now oil pressure registers "normal" but with psi of 129 and psi never varies. It's as if reading is wrong and stuck. Suggestions?

Possible sending switch, to be sure check the actual pressure with a seperate mechanical gage then try groung the sending switch and leaving it unplugged to see if you get different dic readings if so sending unit is bad, if no change something is going on in the dic.