1997 Chevy Silverado location of EBCM

I'm having a problem with my ABS system: abs warning light comes on, then a buzzing noise from under the chassis, and a few seconds of brake loss and stiff brake pedal. If I press the pedal too hard at that point, the truck begins to fishtail. However, the brakes restore themselves after about three seconds of this. Now, I've read everywhere that the EBCM is located underneath the driver seat, attached to the frame rail. However, when I looked there, I saw only the brake and fuel lines, no module, abs pump, or anything else resembling those items. Where else might it be?