detonation sensor

I have a 1994 Nissan Pick up 4X4 3.0 motor. I got a trouble code 34 that states,The detonation sensor circuit is open or shorted, anybody know what this means?
Thanks
Joe

Most newer cars/trucks have at least one or more knock sensors on the eng or transmission some where it sounds like the wire to yours is off/broken or shorted try using a helms manual or equivelant manual to find the knock sensors on your truck and trace the wiring I think you will find a bad place where the wire rubbed or the wire has been disconected.