P0324 Knock Control System Error
OBD-II Trouble Code Technical Description
Knock Control System Error
What does that mean?
This diagnostic trouble code (DTC) is a generic powertrain code, which means that it applies to OBD-II equipped vehicles (Dodge, Ram, Ford, GMC, Chevrolet, VW, Toyota, etc.). Although generic, the specific repair steps may vary depending on make/model.
A stored code P0324 means that the powertrain control module (PCM) has detected a malfunction in the knock sensor control system.
The knock sensor control system typically consists of the knock sensor connector, wiring, and the PCM. The knock sensor is a piezoelectric sensor that is usually threaded directly into the engine block. The location of the sensor varies between manufacturers but most are either in the sides of the block (between water jacket freeze plugs) or underneath the intake manifold. Use caution when removing knock sensors that are in the sides of the engine block as they are often threaded directly into engine coolant passages.
Removal of these sensors, when the engine is warm and the engine cooling system is under pressure, could result in being burned by hot coolant. Before removing the knock sensor, allow the engine to cool sufficiently and drain the coolant into a suitable container for lawful disposal.
The key component of the knock sensor is a piezoelectric sensing crystal. When shaken, or vibrated in this case, the piezoelectric crystal produces a small amount of voltage. Since the knock sensor control circuit is normally a one-wire ground circuit, the voltage generated by the inadvertent vibration is recognized by the PCM as engine knock or ping. The level of voltage produced is dependent on the severity of the vibration encountered by the piezoelectric crystal inside the knock sensor.
Knock sensor control systems are usually arranged with a knock sensor for each engine bank but some manufacturers use as many as one knock sensor per cylinder. Consult a reliable vehicle information source for the configuration of the knock sensor control system for the vehicle in question.
If the PCM detects a level of knock sensor voltage that indicates a spark detonation; it could retard ignition timing to prevent engine damage and no knock sensor control code may be stored (unless it is very severe). If the PCM detects a level of knock sensor voltage that is indicative of a more severe engine noise (such as a connecting rod contacting the inside of the engine block), it may discontinue fuel delivery and ignition spark to the affected cylinder and a knock sensor code will be stored.
There is almost always a very small amount of voltage produced by the knock sensor when the engine is running. This is because no matter how smooth an engine runs, a slight amount of vibration is inevitable. If the PCM detects an unexpected signal from the knock sensor, like battery voltage, complete battery ground, or pulsing voltage, a code P0324 will be stored and a MIL may be illuminated.
Related knock sensor / circuit trouble codes include P0325, P0326, P0327, P0328, P0329, P0330, P0331, P0332, P0333, and P0334.
Code Severity & Symptoms
A stored code P0324 could be a sign of severe internal engine failure. For this cause, it must be addressed with some degree of urgency.
Symptoms of this code may include:
Diminished engine performance Hesitation upon acceleration Loud noises from the engine area Decreased fuel efficiencyCauses
Potential causes for this code to set are:
Defective knock sensor/s Internal engine malfunction Ignition misfire/s Contaminated or substandard fuel Defective knock sensor control wiring and/or connectors Bad PCM or a PCM programing errorDiagnostic and Repair Procedures
A diagnostic scanner, a digital volt/ohmmeter, and a reliable vehicle information source will be n
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