P0328 OBD-II Trouble Code: Knock Sensor 1 Circuit High Input (Bank 1 or Single Sensor)

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P0328 code definition

P0328 is a general OBD2 diagnostic trouble code pointing to a fault within the knock sensor 1 circuit.

What the P0328 code means

The P0328 code is telling us that there is a high input from the bank 1 knock sensor 1. The ECU detects excessively high voltage that is out of range of the knock sensor. This leads to the Check Engine Light being displayed on the dashboard.

What causes the P0328 code?

  • Faulty knock sensor 1, bank 1
  • Open or short in knock sensor circuit wiring
  • Failed ECU
  • Wrong octane fuel or lean air fuel ration
  • Engine is overheating
  • Low fuel pressure

What are the symptoms of the P0328 code?

  • The Check Engine Light is the most noticeable symptom of the P0328 code.

  • The engine may exhibit a loss of engine power and some slight hesitation.

  • In some cases the driver may notice a pinging noise at higher RPMs or an engine that is running warmly.

How does a mechanic diagnose the P0328 code?

  • Uses a scan tool hooked up into the DLC port of the vehicle and checks for any codes present along with any freeze frame data associated with the codes

  • Clears the codes and a test drives the vehicle to duplicate the symptoms and code

  • Listens for engine knocking

  • Performs a visual inspection, looking for any faults

  • Checks the cooling system and engine for any faults

  • Check the fuel octane and fuel system if the engine is knocking

  • Uses the scan tool to monitor the knock sensor voltage for changes if engine isn't knocking

  • Uses a scan tool to check the engine coolant temperature and fuel pressures

  • Tests the ECU, each vehicle has it's own testing procedure for the ECU

Common mistakes when diagnosing the P0328 code

Mistakes can be make when steps are not completed in the proper order or are skipped over completely. This can cause a misdiagnosis such as replacing the knock sensor when really the fuel pressure was causing a knock.

How serious is the P0328 code?

The P328 code should not prevent the vehicle from driving to a safe location once the code is triggered. The symptoms are generally rather mild but like any Check Engine Light should be repaired as soon as possible.

With the P0328 code there is the possibility that a mechanic engine issue or that the engine is running hot. If these symptoms are noticed care should be taken when driving.

What repairs can fix the P0328 code?

  • Repairing or replacing the knock sensor wiring harness
  • Replacing bank 1 knock sensor 1
  • Replacing a faulty ECU
  • Repairing fuel issues
  • Repairing an overheating engine

Additional comments for consideration regarding the P0328 code

P0328 can be a difficult code to diagnose if steps are not followed when performing diagnosis. Many different systems can cause the P0328 and simple things can be overlooked if care is not taken.

A professional level scan tool is essential to properly diagnose this code. These scan tools allow technicians to view live data and voltage from sensors as well as check things like the fuel pressure and engine coolant temp which help pinpoint which system the fault lies with.

Need help with a P0328 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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