P0325 code is a malfunction in the knock sensor which is designed to monitor piston knocking when the engine is running. As a matter of fact, this code can be induced by tapping the side of the engine block with a hammer where the knock sensor is located. This code will come if the engine itself is knocking which could be caused by lean fuel mixture which can occur with detonation on top of the piston. When this happens, the knock sensor will send signal to the computer to slow down the engine ignition timing to prevent further damage to the engine.

Engine detonation can damage the piston and valves of the cylinder head when the detonation is prolong. When this happens, the engine should be stopped and inspection of the knock sensor made. Most of the time, the knocking originates from a defective knock sensor or a faulty wiring connected to the sensor. Once removed, the knock sensor can be measured for resistance and compared to a new one. On other cases, it might be necessary to check the wirings between the knock sensor and the computer pin. If the wirings are proven OK, replacing the knock sensor is usually the common fix otherwise, check with your dealer to have your computer upgraded or re-program.

Accessing the knock sensor is very easy and on most GM engines, the knock sensor is located in the side of the engine block. However, on other types of engine, you might need a wiring diagram so you can identify the color of the wires to the knock sensor. Finally having a wiring diagram or an online mechanic to help you can prevent removal of parts which are not needed.

Thanks!

This entry was posted on Thursday, March 20th, 2008 at 2:58 pm and is filed under Check Engine Light FIXES. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.