What is OBD-II Code P0332 – Knock/Combustion Vibration Sensor B Circuit Low

What is OBD-II Code P0332 – Knock/Combustion Vibration Sensor B Circuit Low

As a vehicle owner, dealing with car issues can be frustrating, especially when you don’t understand the cause of the problem. Fortunately, modern cars come equipped with onboard diagnostic (OBD) systems that help identify potential car problems through OBD codes, making it easier for mechanics to quickly pinpoint the problem.

In this article, we’ll look at OBD-II Code P0332 – Knock/Combustion Vibration Sensor B Circuit Low, what it means, its causes, and potential solutions. Additionally, we’ll cover some frequently asked questions related to this topic.

What is OBD-II Code P0332?

OBD-II Code P0332 is a diagnostic trouble code (DTC) that indicates an issue with the knock sensor. The knock sensor is responsible for regulating the engine’s ignition timing by detecting vibrations caused by engine detonation. Detonation is a condition where the air/fuel mixture undergoes self-ignition, which can cause severe engine damage if left unchecked.

The knock sensor relays this information to the engine control module (ECM), which adjusts the engine timing accordingly. When the knock sensor detects vibration levels outside the predefined threshold, the ECM lights up the check engine light and sets OBD-II Code P0332.

Causes of OBD-II Code P0332

There are several causes of OBD-II Code P0332, including:

1. faulty knock sensor: the knock sensor may be dirty, damaged, or malfunctioning, leading to miscalibrated ignition timing.

2. wiring issues: damage to the wiring connecting the knock sensor to the ECM may cause a disruption in communication leading to erroneous detection of vibration levels.

3. engine issues: problems with the engine’s firing order, engine block, or pistons can cause excessive vibration levels, leading to false detection by the knock sensor.

4. damaged ECM: a damaged or malfunctioning ECM may be unable to communicate effectively with the knock sensor, leading to false detections.

Symptoms of OBD-II Code P0332

Here are some common symptoms of OBD-II Code P0332:

1. decreased engine performance: knock sensors are critical to engine performance, and when faulty, they can cause engine damage, leading to decreased engine performance.

2. illuminated check engine light: the check engine light is an indicator that something is wrong with your car, and if a knock sensor issue is detected, then the check engine light will come on.

3. engine surging: if the engine ignition timing is off, then the engine may surge or accelerate without warning, leading to dangerous driving situations.

Solutions for OBD-II Code P0332

The following are some solutions for resolving OBD-II Code P0332:

1. replace knock sensor: if the knock sensor is faulty or defective, then it needs to be replaced. A professional mechanic can install a new knock sensor to resolve the issue.

2. repair wiring: if there is damage to the wiring, the mechanic can repair or replace the damaged wiring. This is a cheaper option than replacing the entire sensor and is usually only done if the wires are visibly damaged.

3. repair engine issues: if the ODB-II code indicates engine issues, a mechanic may need to repair the engine. This could include replacing pistons or repairing the engine block.

4. replace ECM: if the ECM is the issue, then it may need to be replaced. This is a rare scenario and requires professional diagnosis.

Frequently Asked Questions

1. How do I know if my car has a knock sensor issue?

You will typically notice decreased engine performance and the illuminated check engine light. You might also notice engine surging or acceleration problems.

2. Can I drive my car with OBD-II Code P0332?

It’s not recommended to drive with any OBD-II code as it likely means there is an issue with your vehicle. Continuing to drive with OBD-II Code P0332 can cause engine damage and other problems you could avoid by having the problem diagnosed and resolved.

3. How long does it take to resolve OBD-II Code P0332?

The solution can range from replacing the knock sensor- which can often be repaired within an hour- taking longer if engine problems or wiring are found.

4. How much will it cost to resolve OBD-II Code P0332?

The cost depends on the cause of the issue. Replacing the knock sensor or repairing wiring can be more affordable, while engine problems and ECM problems may be costlier. In general, expect to pay anywhere from $100 – $500.

5. How can I prevent OBD-II Code P0332 from appearing?

Performing regular car maintenance such as oil changes, air filter replacements, and fuel system cleaning can help prevent engine issues which in turn can cause or contribute to OBD-II Code P0332.


OBD-II Code P0332 – Knock/Combustion Vibration Sensor B Circuit Low is an issue that should not be ignored. Failure to diagnose and repair the root cause of the issue can lead to permanent engine damage, poor fuel economy, and vehicle malfunctions. Be sure to take your car to a qualified mechanic at the first sign of trouble with your vehicle’s knock sensor.

Scroll to Top