The code P0328 is called “Knock Sensor (KS) Circuit High Input (Bank 1, Sensor 1)” and refers to a problem detected in the signal from the knock sensor or knock sensor.
This fault code is generic and can be detected with an OBD2 scanner. Error P0328 It is considered a generic code because it applies to all makes and models of cars.
KS Knock Sensor Operation
Knock Sensor (KS) It is installed in the engine and is used to detect “abnormal” or “untimely” knocking in the engine. When detonation occurs, the sensor produces a variable voltage electrical signal, which is sent to the PCM.
The PCM will then change the ignition advance angle to protect the engine and prevent detonation in the next cycle.
The knock sensor has what is known as a piezoelectric crystal internally. This type of crystal produces electrical energy when vibrating. That is, it is a type of transducer that converts changes in physical quantities into an electrical signal.
The signal from the sensor tells the PCM the time and intensity of the knock. The PCM acts accordingly, reducing ignition timing.
Most PCMs are capable of detecting spark detonation trends in the engine during normal operation.
What is Code P0328?
Error code P0328 indicates a high signal level in the knock sensor circuit. That is, the PCM has detected a failure in the signal from this sensor.
Depending on the car model, some engines may be equipped with one or two knock sensors, one for each bank. If your engine has two banks, this code refers to the sensor located on bank 1.
Bank 1 is the one with cylinder 1. If your engine has only one bank, it will have only one sensor.
As we already mentioned, knock sensors (KS) They are included in the engine to detect previous engine detonations, such as punctures and knocks. It is a two-wire sensor powered by a 5V reference voltage, with a return signal connected to the PCM.
Therefore, the P0328 error code means that the PCM (powertrain control module) has detected a reference voltage coming from the knock sensor that is outside the accepted threshold set by the vehicle manufacturer.
This can have several possible causes, as well as show various symptoms detectable by the driver. Let’s keep going.
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Symptoms of Code P0328
Like almost most trouble codes, this code activates the Check Engine light on your dashboard. This light indicates a malfunction that you should check in one of the engine systems.
You may also see some of the following symptoms:
- Low engine power.
- Shaking, as well as knocking in the engine.
- Higher fuel consumption.
- Irregular idle.
- In some cases, the vehicle may exhibit a metallic noise at high RPM.
If the fault is minor, there may be no symptoms other than the Check Engine light and the stored fault code.
Causes of Code P0328
Error code P0328 It can be caused by some of the following problems:
- The knock sensor is defective and requires replacement.
- Defective circuit or short circuit in the knock sensor.
- Incorrect fuel octane rating.
- The PCM module is defective, although it is not common for this module to fail.
- Damaged KS sensor connector.
- Low fuel pressure.
- Incorrect fuel octane.
- Circuit experiencing electrical interference.
- Mechanical engine problem.
Most of the time, the problem is with the KS knock sensor, although you should rule out any other cause through a good diagnosis.
How to Diagnose Code P0328
You should connect the scanner to check if the P0328 code is found alone or is accompanied by other error codes. Combining errors can help you find the fault faster, just by checking what can affect both systems at the same time.
Take note of all the fault codes you find on the scanner when connecting it to your car.
Then erase all the codes with the help of the scanner and take a test drive. For about 10 minutes it will be enough.
If the code appears again after testing, you should perform a visual inspection of the system.
Begin your visual diagnosis by checking all wiring harnesses and connectors related to the system. Inspect electrical circuits, sensors, and connectors that are contaminated with engine oil, coolant, or power steering fluid.
Test the KS sensor
exist two types of sensors on the market. In cars that have this system, but are not recent, you must connect a multimeter set to voltage, between the sensor output wire and ground.
Gently tap the motor near the sensor. You should see the voltage value on the digital multimeter. If you cannot see a change in values, it is because the sensor has stopped working.
To test the resonant type sensor, which is one of the most current cars, connect the digital multimeter in the same way. But instead of touching the engine block, you should try to start the car and make it shut down due to lack of fuel.
It is necessary to remove the fuel pump relay for the car to start and then shut down due to lack of fuel.
Start the engine, run it, and keep your foot on the brake. As soon as the car starts to run out of fuel, it will start to detonate and stall.
At this point, you should see an output voltage on your multimeter, sent by the sensor. If you don’t see the voltage, the sensor is bad.
Check the electrical circuits
If the knock sensor is working properly, but the code P0328 is still on, you need to check the sensor circuit.
With the multimeter set to resistance measurement, connect one side to the KS sensor connector wire. And the other side to the KS sensor input on the PCM module. This way you can check the continuity between the PCM and the KS sensor.
Now it is necessary to check the grounding. “Not So New” knock sensors, with older technology, have a direct ground connection, while newer technology sensors typically have the ground connection separate from the main sensor circuit.
When measuring, you should see a value of approximately 12 volts, which indicates a good ground connection. Otherwise, you should look for a faulty or damaged circuit.
How to Fix Code P0328
The repairs to be made to resolve this code will depend on the results of the diagnosis. You should not replace parts and components without being sure that this is really the fault.
If there is engine knocking (knocking), the first thing you should do is fix the mechanical problem, if it has one, and retest the vehicle.
You should also make sure the car is using the correct octane fuel. Some engines may require premium fuel, so it’s worth checking your owner’s manual.
Additionally, the most common source of this problem is in the knock sensor itself, the connectors, or the wiring from the sensors to the PCM. Therefore, these things should be checked first and repaired or replaced as necessary.
Let’s see the repairs error code P0328:
- Repair or replacement of electrical wiring and sensor connectors.
- Changing the quality of fuel for one with a better octane rating. This should be done according to the recommendations given by the manufacturer.
- Repair or replacement of the faulty PCM. In this case, you may also need a complete reprogramming.
- Replacing the KS sensor. If the sensor is damaged, it is not recommended to attempt to repair it, it must be replaced. Sensor repairs usually end up causing bigger headaches.
Common Errors When Diagnosing and Repairing Code P0328
The most common error with this code is replacing the sensor without verifying the other components of the system. Many times, the fault may be in a poor connection, damaged wiring, or the PCM.
Performing a good diagnosis is necessary to resolve OBD code problems. This way you save time and money.
Is Code P0328 Serious?
Yeah, the code P0328 is of moderate severity. Diagnosing error code P0328 can be difficult if the correct steps are not followed, and many different aspects and systems of the vehicle can be missed.
Therefore, a scan tool is very important for a complete diagnosis of this code.
Although the symptoms are quite mild and do not always cause serious driving problems, it does cause the engine to run hot, making it crucial to fix this problem.
Plus, no one likes that annoying activated Check Engine light on the dashboard.
How to Avoid Code P0328?
You can avoid this and other codes with the routine preventive maintenance you should do on your car. Periodically review the condition of the cables, connections, and sensors to avoid major or worsening failures.
When the failure occurs through the wiring harness or circuit connections, it is perfectly avoidable. But if the fault is in the sensor itself, you won’t know it will fail until the code is activated.
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Although most of the cases in which the code P0328 is activated due to damage to the sensor itself, you should not change it without first testing it and making sure that the fault is really located there.
By carrying out the proper diagnosis with your OBD 2 and a digital multimeter, you will be able to detect the fault and carry out the repair. If you consider that you cannot carry out the diagnosis yourself, take your car to a specialized service.
If you want to know other articles similar to Code P0328. Causes, Symptoms, Diagnosis, and Repair you can visit the category Fault Codes.