If we are talking about '96 gtv, i'm pretty shure it does not have ebd. that was introduced somewhere after '98 gtv's. I know, the manual still says that 5.3 has ebd, but not early years. Plus in that case your car has to have OBD II connection. And abs sensors are of that small type, using magnetic stripe on wheel hubs instead of toothed gear. Luckly 5.3 without ebd and obdII have seperate cable, wich can be used to read errof/fault codes. Cable has 3 pins. somewere near abs unit itself. one of the pins have to be connected to ground, key turned, and flashing light on dashboard gives the fault code.
My 2001 also has 5.3 unit with ebd. Means there are 8 outlet pipes from abs unit. Only possability to diagnose it is through OBD II. And in 5.3 with ebd, if it fails, you get two lights in dashboard - handbrake signal (!) and ABS warning light.