How To Test a 3-Wire Crank Sensor With a Multimeter

One of the most important parts of the crankshaft is the 3 wire crank sensor. The 3 wire crank sensor is a multifunctional device, and it can detect the RPM of the engine. In addition, it can detect the speed as well as the setting of the timing of the ignition. A bad crank sensor can cause problems for your car. Some of these problems include increased fuel consumption, engine resistance, stalled acceleration, and sudden RPM drops.

A car that has a well-working 3 wire crank sensor can find out how efficient the performance is regarding the gas mileage, emission production, and power output. If you’re looking to buy a new or a used car, the 3 wire crank sensor can help you determine if the vehicle will meet your needs or not, and if the sensor is out of order, then you may not be able to do so.

To test whether a 3 wire crank sensor is working properly or not, you can use a multimeter.

Symptoms of A Defective 3 Wire Crank Sensor:

One of the most common signs of an out-of-order 3 wire crank sensor is the check engine light. The check engine light turns on in most cases and shows that there is a defect in your engine, which is most likely with the 3 wire crank sensor. Additionally, your car may have a number of other symptoms, too, one of them being higher fuel consumption.

Moreover, there are vibrations in the engine that causes a juddering effect. You may be getting a slow response from the accelerator, experiencing problems with erratic starting, stalling, backfiring, and other engine issues. While these indications are not exclusive to a 3 wire crank sensor damage, they are the most occurring symptoms. It is best to check your car and find out if the 3 wire crank sensor is actually damaged or not.

It is quite easy to measure the readings required to test your sensor, and you can do with a handy device known as a multimeter. It finds out the current, resistance, and voltage of a circuit, and you can use the device to test the circuit of your 3-wire crank sensor.

How To Test 3-Wire Crank Sensor With a Multimeter:

In addition to the indications mentioned above, the car may not even start, which can lead to a complete engine failure. If you are experiencing similar problems, it may be time to test your 3 wire crank sensor with a millimeter.

Let’s go through the process step by step below.

Find the Position of the Wires:

First, see where the wires are located. You will need to find the signal wires, the ground wires, and the power wires. Most user manuals or owner manuals contain information regarding the location of the wires.

Prepare The Multimeter:

After finding the location of the wires, you need to prepare the multimeter for examining the 3 wire sensor. You will need to change the settings of the multimeter in order to make correct measurements. For testing the circuit of the 3 wire crank sensor, set the multimeter to DC volt.

Touch The Wires:

Before doing this step, make sure that your car engine is turned off. It is essential that you do this because proceeding with this step may be dangerous if your car engine is running. Then, turn the ignition key on. Recheck if you have the correct wires at hand, take the black cable from the multimeter, and touch it with the ground wire. Make sure to connect the black cable with the ground wire only.

Then, identify the other cables in the 3 wire crank sensor. Take the other multimeter cable and connect it with the power wire.

Check the Readings:

Note down each of the readings displayed on the multimeter after you touched the wires in the previous step. Look into the multimeter readings and write the correct readings on a note nearby. Typically, there are values given in the owner’s manual. Compare your own findings with the values of the owner’s manual and see if the figures are different or not.

Touch The Wires Again:

Now, you’ll need to touch the wires again as you did before. The only difference between this time and the last one would be that the car engine will be on. Because the car engine was off in the previous measurements, the figures will be different from those. Start the engine and connect the black cable of the multimeter with the ground wire. Similarly, touch the red cable of the multimeter with the signal wire of the 3 wire crank sensor.

Check the Readings Again:

Again, note down the readings that appear on the multimeter. Compare the figures once again with the ones already stated in the user manual.

Interpret the Findings:

Now that you have all your findings at hand, you can identify if your 3 wire crank sensor is working or not. Check the values and compare them with the ones in the manual. If the readings that you measured on the multimeter are lower than the ones mentioned, it means that your 3 wire crank sensor is most likely defective.

Similarly, if there is no signal at all on the multimeter, it also hints that your 3 wire crank sensor is defective. The 3 wire crankshaft position sensors can wear easily, especially if they are subjected to heavy usage. So, if with the help of a multimeter you find out that your 3 wire crank sensor is defective, get it replaced with a new one.

Some specific problems mentioned above direct straight towards a 3 wire crank sensor failure, and these include the car’s acceleration, the performance, and the engine. However, you can’t make a guess based on just the symptoms, so it is better to check the sensor with the help of a multimeter. By using the method mentioned above, you can just do so and save yourself a trip to the mechanic!

Also, learn how to flush an automotive AC system.

Daniel Wood

Daniel, who is a mechanical engineer and hobbyist mechanic by profession has been specializing in electronic equipment for the past four years. He worked as an engineer at one of these manufacturing plants that specializes exclusively on this type equipment before opening up his own shop where he does research into different machines all day long!