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P0332 OBD Fault Code (Causes & Fixes)

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Last Updated on: 7th September 2023, 12:36 am

The P0332 fault code stands for: Knock Sensor 2 Circuit Low Input (Bank 2)

This fault code is a sign of a potentially serious problem and may cause engine damage if left unfixed, avoid driving the vehicle if this code appears and fix as soon as possible.

If the knock sensor 2 circuit outputs a low input signal, the ECU will this fault code, this can also trigger the check engine light (CEL) to illuminate.

In this article, we’ll explain what the P0332 OBD fault code is, what the signs and causes are, how serious it is and possible fixes.

What Does P0332 Mean?

P0332 is a diagnostic trouble code (DTC) which stands for “Knock Sensor 2 Circuit Low Input (Bank 2)”.

The knock sensor has the job of alerting the ECU when the engine experiences knocking (when the air/fuel mixture combusts prematurely).

A P0332 fault code basically means there is an issue with the engines knock sensor.

If the ECU receives an incorrect knock sensor reading, it wont be able to deliver the correct adjustments to the engines operation. This can lead to a variety of problems.

How Serious Is It?

The occurrence of engine knocking hinders the engine’s ability to operate smoothly and efficiently, potentially leading to damage of its components if left unaddressed.

In the event of a malfunctioning knock sensor, the ECU won’t be able to appropriately fine-tune the engine’s performance and operation.

This can result in an engine that runs unevenly, overheats, experiences decreased fuel efficiency, and encounters various other potential problems.

This becomes particularly crucial if your vehicle is high-powered, equipped with a turbocharger or supercharger, or has undergone upgrades, tuning or remapping.

Moreover, when engine knocking takes place, an excessive amount of nitrogen oxides (NOx) is emitted, causing the vehicle to fail emissions tests.

Therefore, a P0332 code is a fairly serious issue which can lead to further engine damage if left unfixed.

Can I Still Drive?

It’s not recommended to drive a vehicle if it has a P0332 fault code. Since the knock sensor plays a vital role in the safe functioning of the engine, if it’s faulty it could quickly lead to engine damage.

Signs & Symptoms

In some cases, the only indication of a P0332 DTC is the check engine light turning on.

You may notice the following signs:

  • The check engine light illuminating
  • The car may go into a failsafe mode (limp mode) and the engines power will be reduced and the RPMs will be limited
  • Engine knocking may occur, sometimes you can feel or hear this
  • The engine may overheat, even while driving normally
  • A loss of engine performance and power

Other issues and signs can arise over time, such as poor engine running and idle, rattling and knocking noises, etc.

Possible Causes

Oftentimes the knock sensor itself is the issue. However, the following may also cause a P0332 fault code.

  • A cooling system issues or malfunction
  • An unusually lean air/fuel ratio
  • A problem with the knock sensor circuit or one of its connections
  • EGR (exhaust gas recirculation) system failure

Diagnosing

Follow the steps below in order to diagnose a P0332 trouble code.

  1. Begin a visual examination of the sensor and its wiring after validating the code with an OBD scanner.
  2. Examine the circuit, connections, and other associated parts using a multimeter and other diagnostic equipment.
  3. Clear the code from the OBD system and retest it by turning on the car after each test or repair.
  4. Conduct a test drive to confirm that there is no intermittent issue that has to be resolved.

It’s important to properly diagnose and validate the P0332 error code. In some circumstances, the wiring or connections is the issue and not the knock sensor itself.

Sometimes the issue may be with the cooling system or the EGR system, in these cases simply replacing the knock sensor would not resolve the issue and the fault code would return.

How to Fix

Once you’ve verified the P0332 OBD fault code is the issue you can follow the steps below to fix it.

It’s a good idea to obtain the technical service bulletins (TSB) for the vehicle as they may provide useful diagnostic information which could help you diagnose and fix the issue.

Possible fixes for the P0332 fault code include:

  1. In the sensor circuit, replace frayed or damaged wiring and connectors.
  2. Make sure that the knock sensor and circuit are properly grounded.
  3. Make that the knock sensor voltage is within the specified range using a multi meter.
  4. Check the voltage of the temperature sensor and confirm it’s within the required range. If not, the temperature sensor may be providing incorrect readings, resulting in a lean operating state and engine knock. Replace the temperature sensor and wiring if that’s the issue.
  5. If the previous fixes didn’t work, you may need to replace the engine knock sensor.
  6. Rarely you may need to replace or reprogram the ECU. Sometimes a P0332 fault code could also be related to the EGR or cooling system.
  • Andy Lewin

    Andy Lewin is a senior mechanic, ASE qualified master technician, and an experienced automotive engineer. He's passionate about serving the automotive community with the highest-quality and trustworthy information on all things automotive. He loves to write about car repairs, maintenance, car modifications and tuning, faults, and much more.

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