The P0332 OBD2 code activates when the bank 2 knock sensor isn’t sending a signal to the engine computer. The knock sensor is your engine’s first line of defense against knocking, a serious problem that can cause significant engine damage if left unchecked.
P0332 is not a code to be taken lightly. Most engines drive rough when there’s a P0332 trouble code. You’ll experience increased emissions and reduced fuel efficiency, problems you’ll want to clear up right away.
Play close attention to all the codes you read when you scan your car. While P0332 is often caused by faults in the knock sensor or surrounding wiring, it can be linked to other engine systems, too. You can use other codes that come up to guide your diagnosis and find the real root of your problem.
Contents
P0332 Code Definition
Knock Sensor 2 Circuit Low Input (Bank 2)
What does P0332 mean?
When the air/fuel mixture in your engine is exploding, this is known as “knocking” or “pinging”. When this happens, less power is delivered to your engine, and more harmful emissions get into your exhaust. Prolonged knocking can also cause serious damage to internal components.
The knock sensors in your engine are there to notify you when your engine is knocking. The powertrain control module (PCM) or engine control module (ECM) monitors the readings from the knock sensors, both to detect knocks and to ensure the sensors are operating properly.
If the PCM or ECM receives a reading from the knock sensor that is too low, the P0332 trouble code is set. When this happens, the engine computer is not able to communicate effectively with the sensor to detect knocking problems. Typically the code will trigger when the knock sensor has an output below .5 volts.
The P0332 OBD2 code points specifically at the second knock sensor on bank 2 of your engine. Bank 2 is the side that contains the second cylinder. You may see this code alongside other knock sensor DTCs, which include P0325-P0334.
What are the symptoms of the P0332 code?
In some cases, you won’t experience any drivability symptoms with the P0332 trouble code. Most of the time, however, you’ll notice one or more of the symptoms below:
- Activation of the check engine light
- Engine pinging or knocking during acceleration
- Engine operating at higher heat than normal
- Reduced engine power
- Reduced fuel economy
- Increased harmful emissions
- Fluctuations in engine RPMs
- Engine hesitation on acceleration
What are the causes of P0332?
- Faulty knock sensor
- Open or short in knock sensor circuit
- Damaged or faulty wiring around knock sensor
- Air/fuel mix is too lean
- Faults in the cooling system
- Faulty components in exhaust gas recirculation (EGR) system
- Malfunctioning PCM or ECM (less common)
How serious is the P0332 code?
The P0332 trouble code is very serious. Knocking can cause long-term damage to your engine, so it’s very important your engine computer be able to detect and adjust to them. You should stop driving your vehicle and repair the problem immediately, especially if you’re experiencing drivability issues.
How to diagnose and fix the P0332 code
Tools you’ll need:
- OBD2 scan tool
- Digital multimeter
- Use an OBD2 scan tool to read all codes from your vehicle. Make note of any codes that appear alongside P0332, especially codes that indicate a lean air/fuel mixture or issues with the EGR system and cooling system. Clear all codes and test drive your vehicle, then re-scan to see if P0332 comes back.
- Read the freeze frame data from when the error occurred. If the knock sensor is sending a signal to the PCM, the engine may be receiving incorrect data about the coolant temperature. This is especially likely to be the cause if your engine has been running hotter than normal. Test the coolant temperature sensor using a digital multimeter, taking readings when you start the car and after it’s been allowed to idle to operating temperature. Compare the readings to the stated specifications in your manual. Replace the sensor if necessary.
- If the knock sensor isn’t sending a signal to the PCM or ECM, the problem may be with the sensor or the wiring. Inspect the wires around the knock sensor, paying close attention to the ends, which may fray. Replace any damaged or faulty wires, and ensure all connections are secure.
- Verify that the knock sensor is receiving the proper voltage from the engine, and check for opens and shorts to the ground.
- Use an OBD2 scanner to check the readings from the knock sensor again. If it’s still not sending a signal, the sensor itself is likely the problem. Test the resistance of the knock sensor, comparing it to the specifications in your repair manual.
- Replace the knock sensor if the tests determine it’s faulty. You may want to consult with a mechanic before you take this step. It’s often recommended to replace the entire wiring harness along with the knock sensor in the case of P0332 codes.
- If the P0332 code still will not clear after replacing the knock sensor, you may have a more serious issue with your engine computer. Consult with a mechanic to determine the best next step.
Common mistakes to avoid while diagnosing the P0332 code
Some inexperienced mechanics immediately replace the knock sensor when they read a P0332 DTC. The problem is often with the wiring, however, and can be caused by faults in other systems, as well. Make sure you conduct a thorough diagnosis before replacing any components.
Tips to avoid P0332 in the future
Issues with the wiring are a common cause of P0332, as well as a host of other diagnostic trouble codes. Wires can be damaged by the heat from nearby components, or jostled loose by the vibrations of your engine, so it’s a good idea to give your engine’s wiring a visual inspection as part of your regular maintenance routine.
Read more: Autel MaxiLink ML529 OBD2 Scanner Review
