P0327 Knock sensor malfunction code

DTC P0327 Technical Description

Low input signal in the knock sensor 1 circuit (bank 1 or separate sensor)

DTC P0327 refers to a low voltage condition in the vehicle's knock sensor circuit. Specifically, this code refers to the number 1 engine bank knock sensor on V-configuration engines.

However, to better understand the severity of the P0327 DTC, you must first be familiar with the theory behind the operation of the knock sensor.

Most modern cars are equipped with a so-called knock sensor. This type of sensor monitors motor harmonics, trying to recognize and isolate any deviations.

When working properly, the engine knock sensor alerts the motorist to abnormal engine vibrations by illuminating the vehicle's check engine light. Most knock sensor "events" are associated with marginal combustion.

In the case of a DTC P0327, the engine management software assumes that the sensor in question cannot provide accurate feedback. This, in turn, nullifies the vehicle's ability to distinguish between normal and abnormal engine vibration, thereby making it somewhat more vulnerable to subsequent wear.

What does trouble code P0327 mean?

This Diagnostic Trouble Code (DTC) is a generic transmission code, which means it applies to OBD-II equipped vehicles. Although general, specific repair steps may differ depending on the brand / model.

The knock sensor tells the engine computer when one or more of your engine's cylinders "knock", ie, they explode the air / fuel mixture in such a way as to provide less power and cause engine damage if it continues to run.

The computer uses this information to tune the engine so that it does not knock. If your knock sensor on block # 1 generates a low output voltage (possibly less than 0.5V) then it will trigger DTC P0327. This Code P0327 may appear intermittently, or the Service Engine light may remain on. Other DTCs associated with the knock sensor include P0325, P0326, P0328, P0329, P0330, P0331, P0332, P0333, and P0334.

Symptoms

You may notice handling problems, including fluctuations in engine speed, loss of power, and possibly some fluctuations. There may be other symptoms as well.

DTC P0327 is often accompanied by a number of additional symptoms, most of which vary in severity. Recognizing these symptoms is often helpful when trying to pinpoint the root cause of such problems.

The following are a few of the most common symptoms associated with DTC P0327.

• Check engine light
• RPM fluctuation
• Engine misfiring
• Vibrations under load
• Decreased productivity

Also, in some cases DTC P0327 is not accompanied by any additional symptoms, although this is quite rare.

Causes of the P0327 code

DTC P0327 can be caused by a variety of underlying problems, some of which are much more common than others. Understanding these potential causes can help you get your vehicle repaired faster.

The following are a few of the most common causes of a P0327 DTC.

• Knock Sensor Circuit Wiring Problems
• EGR Related Defects
• Cooling system problems
• Compromised PCM /ECM
• The knock sensor is defective and needs to be replaced.
• Open / short circuit / malfunction in the knock sensor circuit
• PCM / ECM out of order

Possible solutions

• Check the resistance of the knock sensor (compare with the factory specifications)
• Check for open / frayed wires leading to the sensor.
• Check wiring and connections to / from the knock sensor and PCM / ECM.
• Make sure the correct voltage is supplied to the knock sensor (for example, 5 volts).
• Check for proper grounding of the sensor and circuit.
• Replace the knock sensor.
• Replace PCM / ECM.

The following steps can be used to diagnose and resolve the root cause of your vehicle's active DTC P0327. As always, be sure to read the factory service manual ( print or online ) for your particular vehicle before proceeding with such repairs.

#1 - Check for Additional DTCs

Check for additional DTCs before starting the diagnostic process. Any such codes that are present must be carefully diagnosed before proceeding.

#2 - Inspect knock sensor wiring

Start by inspecting the affected knock sensor as well as any related wiring. When carrying out such a check, it is also advisable to check the integrity of the corresponding sensor connector. Any damage or irregularities must be repaired immediately.

#3 – Check Power/Ground

Then check for power and ground inputs (as specified by the vehicle manufacturer) at the appropriate knock sensor with a good quality DMM. If any of the channels are missing, further input circuit troubleshooting will be required.

#4 – Resistance Check

Now you can remove the corresponding knock sensor and check its effective resistance. Most manufacturers indicate that sensors of this design must have a resistance of more than 0,5 ohms. Resistance below this degree will require replacement of the sensor.

#5 – Check sensor feedback

Assuming your car's knock sensor resistance is within specification, you'll need an oscilloscope to read and decipher the feedback from the sensor itself.

Any and all feedback should reflect manufacturing specifications and not deviate from a predetermined waveform or duration. If no abnormalities are found in this feedback, it is most likely a faulty or defective PCM/ECM.

Is code P0327 serious?

Compared to other trouble codes, DTC P0327 is often considered a moderate priority code. There is generally a small risk of additional damage resulting from driving with DTC P0327 active.

This is due to the fact that this code indicates not so much work-related problems as a malfunction of a particular sensor. Simply put, code P0327 describes the relative inability of the car's knock sensor to function properly.

Similarly, the feedback provided by the vehicle's knock sensor has little to do with further ECM/PCM calculations, meaning that such data is not critical to efficient engine operation. Lack of proper operation of the knock sensor is unlikely to prevent the vehicle from operating at a suitable degree of efficiency.

However, you should take the necessary time to diagnose and correct the root cause of your vehicle's DTC P0327 whenever practicable. Performing such a repair restores the operation of the knock sensor, thereby eliminating your car's annoying check engine light in the process.

How to Fix P0327 Engine Code in 2 Minutes [1 DIY Method / Only $10.67]

Need more help with your p0327 code?

If you still need help with DTC P0327, post a question in the comments below this article.

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