Due to the Piranha Prime's proximity to the breached warehouse depot, Venerable Tusa could not risk a transmission.
The signals released by his mech would definitely tip off the unknowns of his presence.
So far, Venerable Tusa had been careful to travel low on the ground and let all of the widespread jamming and interference obscure his prime mech.
He had been careful to control the emissions of his mech. By outputting less heat, he not only conserved his energy, but also lowered the chance of getting spotted from a distance.
Still, against powerful opponents, this trick was bound to fail. Military-grade sensor systems were much better equipped to peer through jamming and spot anomalous signal patterns.
The fact that the looters failed to detect his Piranha Prime at its current distance suggested that the unknowns belonged to a private faction, but that made little sense.