The use of textile yarns as data transmission media enables the design of non-obtrusive well-fitting garments as wearable systems. However, textile conductive yarns show impedances higher than those presented by common metal conductors and these values can change with the textile condition and level of stretching, affecting the integrity of the transmitted signal. This work proposes a built-in self-test methodology to test textile yarn interconnections for conventional stuck-at, open and short faults, as well as to verify signal integrity. The test procedure being proposed relies on sampling to generate a digital signal that results from comparing the received signal with pre-defined voltage levels. The obtained signature allows to verify signal integrity parameters: VLmax, VHmin and rise and fall times. Simulation results confirm the validity of the methodology being proposed.