Replaced laser pick up, error 11 ???? Pioneer DEH-2400

I don't get it. I pulled the working pick up out of this one to fix
another
deck (same model) Then, I ordered a new pick up and when it arrived
I installed it. Now, the disc spins, sled moves to center position and
laser makes 2 attempts to read, then displays error 11.

Pioneer DEH-2400
I need some feedback here.

yours truely,
tired and frustrated