My guess is that you dont have the LSS module, but its not hard to add. As said above, first check and make sure you see the LSS module and the second LSS transducer. The module looks like a small car stereo amplifier. The transducer is large like the posts above says. If you have these then it may be the LSS isn't turning on (there may be switch you dont know about). When I added my LSS I had trouble getting the HDS to recoginze it. I had to update my firmware to get them to talk. So I feel your pain. I hope this helps.