P0328 Knock Sensor Circuit High Input

Description and meaning of DTC p0328

This diagnostic trouble code (DTC) is a generic powertrain code, which means that it applies to OBD-II equipped vehicles. Although generic, the specific repair steps may vary depending on make/model. Knock sensors are used to detect engine pre-detonation (engine knock or ping). The knock sensor (KS) is usually a two wire sensor. A 5 volt reference is supplied to the sensor and there is a signal return from the knock sensor to the PCM (powertrain control module). The sensor signal wire informs the PCM when a knock occurs and in what degree of severity. The PCM will retard the spark timing to avoid pre-detonation. Most PCMs have the ability to learn spark knock trends in the engine during normal operation. A P0328 code is a generic DTC, thus it applies to all makes of vehicles, and refers to a high output voltage of the knock sensor. In many cases, this means the voltage is above 4. 5V but that specific value depends on the specific make and model of vehicle. This code refers to the sensor on bank #1.

p0328 diagnostic trouble code symptoms

Symptoms of a P0328 DTC may include:MIL (Malfunction Indicator Lamp) illuminationAudible knocking from the engine compartmentPinging from engine under accelerationLoss of powerIrregular RPM

DTC p0328 - possible causes

Potential causes of a P0328 code include:Knock sensor connector is damagedKnock sensor circuit is open or shorted to groundKnock sensor circuit is shorted to voltageKnock sensor has failedLoose knock sensorElectrical interference in circuitLow fuel pressureIncorrect fuel octaneMechanical engine problemFailed/faulty PCM

How to fix OBD-II diagnostic trouble code p0328

If you can hear engine knock (detonation), first fix the source of the mechanical problem and retest. Ensure the correct octane fuel was used (some engines require premium fuel, check the owners manual). Aside from that, for this code, most likely the problem will lie either with the knock sensor itself or the wiring connectors going from the sensor to the PCM. Realisitcally, for the DIY vehicle owner, the best next steps are to measure the resistance between the two knock sensor wire terminals where they go into the PCM. Also, check the voltage of the same terminals. Compare those numbers to the manufacturer's specifications. Also, check all wiring and connectors leading from the knock sensor back to the PCM. In addition, you should also check the resistance using a Digital Volt Ohm Meter (DVOM) of the knock sensor itself, compare it to the vehicle manufacturers specification. If the knock sensor resistance value is out of spec, then it needs to be replaced. Other knock sensor DTCs include P0324, P0325, P0326, P0327, P0328, P0329, P0330, P0331, P0332, P0334

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