Biofilm formation begins when bacteria contacting a surface induce cellular changes to become better adapted for surface growth. One of the first changes to occur forPseudomonas aeruginosaafter surface contact is an increase in the nucleotide second messenger 3’,5’-cyclic adenosine monophosphate (cAMP). It has been demonstrated that this increase in intracellular cAMP is dependent on functional Type IV pili (T4P) relaying a signal to the Pil-Chp system, but the mechanism by which this signal is transduced remains poorly understood. Here, we investigate the role of the Type IV pili retraction motor PilT in sensing a surface and relaying that signal to cAMP production. We show that mutations affecting the structure of PilT and in particular ATPase activity of this motor protein, reduce surface-dependent cAMP production. We identify a novel interaction between PilT and PilJ, a member of the Pil-Chp system, and propose a new model wherebyP. aeruginosauses its retraction motor to sense a surface and to relay that signal via PilJ to increased production of cAMP. We discuss these findings in light of current TFP-dependent surface sensing models forP. aeruginosa.