Pressure Decrease

If during the pressure hold mode the Electronic Brake (Traction) Control Module (EBCM/EBTCM) still senses wheel speed slip it will decrease pressure to the brake. It does this by leaving the Hold (Inlet) valve closed and opening the Release (Outlet) valve in the Brake Pressure Modulator Valve (BPMV). The excess fluid is stored in the accumulator until it can be returned to the reservoir by the return pump.