Toyota Repair: knock sensor warning, chilton manual, knock sensor

Question
1989 toyota pickup, 3VZE, 205K miles.

I am getting a "52" error code, which the manual tells me is a  knock sensor warning.  However, I cannot find the stupid sensor to check the wiring, sensor itself, etc.  My Chilton manual does not have an accurate diagram of the engine and sensor locations, and for some reason the factory manual is even more vague when it comes to the knock sensor's location.

i have found one sensor below the distributor on the left (driver's) side of the engine, a little below where the thermostat is housed.  could it be that?  doesn't look like the ones in the manual...

Answer
On this wngine the knk sensor is located in the middle of the engine under the intake manifold, to get to it the entire intake system has to be removed including the manifold, check the connector for the sensor and make sure it is plugged in, the connector is located on the driver side of the engine just below the fuel rail, it is a black round connector, if it's connected and the code is still there the only solution is to replace the knk sensor and the connecting wire.