P0325 error code is a failure in the knock sensor which is designed to monitor engine piston knocking when the engine is running. In fact, this error 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 take place with detonation on top of the piston. When this happens, the knock sensor will transmit signal to the computer to retard the engine ignition timing to prevent additional damage to the engine.

P0325 error code induced engine detonation which can damage the piston and cylinder head valves when the detonation is prolong. When this happens, the engine should be stopped and immediate inspection of the knock sensor circuit should be made.

Keep in mind, getting P0325 error code does not mean that the knock sensor itself is defective right away. If the sensor is ok, get a wiring diagram and see which engine part or wire connection is included in the knock sensor circuit. One common culprit coming from this technique is a bad ground wire which becomes obvious when it is used as a common connection between the knock sensor and other engine sensors.

Another most common fix when P0325 error code comes around is a defective or dirty mass sensor. When coupled with hesitation and the mass sensor has not been replaced for years and prolong used of a dirty air filter, now is the best time to change this load sensor (mass sensor is called a load sensor since it monitors the engine during acceleration). Not far behind is also your common vacuum leak when can cause misfiring that will be detected by the knock sensor. A lot of this is usually accompanied by P0171 lean mixture code.

When fixing P0325 error code 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 to find it. Finally having a wiring diagram or an online mechanic to help you trace the knock sensor circuit can prevent removal of good parts which are not needed.

Quick ATS Tip:

Finally, beware when troubleshooting a P0325 error code: when you see this code alone in the scanner, most likely the problem is the knock sensor related circuit. If accompanied by other codes, make sure to check first for other defective sensors or go to your basic ATS troubleshooting techniques.

Bye!