How to check a knock sensor with a multimeter
Content
The knock sensor is an important component in the operation of your vehicle. It is responsible for detecting detonation or detonation of the engine. This is very important for the efficient operation of your vehicle, as detonation can damage the engine.
Therefore, we recommend that you periodically check the knock sensor to make sure it is working properly. If you have a problem with your knock sensor and need to check it or perform scheduled maintenance, we can help. In this post, we will learn how to test the knock sensor with a multimeter.
To test the knock sensor, follow these steps:
Locate your vehicle's knock sensor on the engine manifold. Disconnect the wiring harness from the knock sensor by pulling on the base of the wiring harness where it contacts the knock sensor. Take a multimeter and connect its wire to the knock sensor. Touch the multimeter's negative lead to a grounding point, such as the negative battery terminal. If your knock sensor is in good condition, you should see continuity. Your multimeter should read 10 ohms or more.
What is detonation?
This is a situation where the mixture of fuel and air in your car explodes quickly instead of burning evenly. If your knock sensor is not working properly, it cannot detect engine knock. A properly functioning knock sensor usually has continuity - the presence of a current electrical circuit between the wire and the sensor. Without continuity, the knock sensor may not perform optimally. Luckily, you can check the integrity of the knock sensor with a multimeter.
Do you suspect a malfunctioning knock sensor?
When you have a bad knock sensor, several things happen. Some telltale signs include low power, lack of acceleration, popping sound after checking, and lost fuel mileage. Pay attention to the sounds of the engine - loud knocks that only get worse over time. If you hear these noises, the fuel and air in the cylinder may be igniting instead of reaching the combustion point. (1)
Diagnosing a Faulty Knock Sensor
You can perform a diagnostic test on a failed knock sensor in several ways. For example, if the check engine light is on, this is a sign of a problem with the knock sensor circuit. As mentioned earlier, poor engine performance could potentially indicate a faulty knock sensor. Checking for Diagnostic Trouble Codes (DTCs) can help you find any existing problems that require immediate attention. A visual inspection and finally a direct test of the knock sensor with a multimeter will also do.
How to check a knock sensor with a multimeter
Below is a step-by-step instruction on how to check the knock sensor with a multimeter:
- Park the vehicle on a level surface, apply the emergency brake and turn off the engine. After opening the hood of the car, turn on the engine. Opening the hood with the engine off helps prevent possible injury.
- Locate your vehicle's knock sensor on the engine manifold. It is usually installed in the middle of the engine under the intake manifold. To avoid unnecessary trouble finding the knock sensor, refer to the repair manual. A detailed engine diagram will come in handy. (2)
- Can you find the wiring harness? Disconnect it from the knock sensor by pulling on the base of the harness where it contacts the sensor.
- Take a multimeter and connect its wire to the knock sensor. Touch the multimeter's negative lead to a grounding point, such as the negative battery terminal. If your knock sensor is in good condition, you should see continuity. Your multimeter should read 10 ohms or more.
What if there is no succession?
A multimeter test result of the knock sensor that shows no continuity indicates that the sensor should be replaced.
Summing up
A knock sensor that is not working can cause the engine to knock. Worst of all, the computer may not detect the ping. To ensure optimum engine performance, consider replacing a failed knock sensor.
Take a look at some of our articles below.
- How to test a three-wire crankshaft sensor with a multimeter
- How to check sensor 02 with a multimeter
- How to check the car ground wire with a multimeter
Recommendations
(1) combustion - https://www.britannica.com/science/combustion
(2) diagram – https://www.edrawsoft.com/types-diagram.html
