Circuit Description
WARNING: This page is about a different car, the 1995 Toyota Land Cruiser. However, it is still accessible from the selected car via links, so may be relevant.
See CODES P0325 & P0330 - KNOCK SENSOR NO. 1 (FRONT) & NO. 2 (REAR) CIRCUIT. Code is set when ECM is detected to be faulty in regard to knock control. ECM is the only possible cause.