Multimeter,

How to Test a Hall Effect Sensor with a Multimeter (4 Steps)

Power loss, loud noise, and a feeling that the motor is somehow blocked are signs that you may have a dead controller or the hall effect crank sensor inside your motor has an issue.

This article shows how to test a vehicle’s Hall effect sensor using a multimeter, primarily the sensor’s voltage.

In brief, to test a Hall effect sensor with a multimeter:

  • Set a multimeter to measure up to 20 DC volts.
  • Connect the multimeter’s black probe to the Hall sensor’s ground pin(or a ground point on the vehicle) and the red probe to its power supply pin.
  • Check the reading on the multimeter. It should be around 12-13 volts.

Let’s get started testing a Hall effect sensor with a multimeter. Besides testing for the correct voltage, I’ve also covered resistance and current tests and 3-wire hall effect sensors.

The Hall Effect Sensor and Why it May Fail

A hall effect sensor is a transducer that generates an output voltage in response to a magnetic field.

It monitors position and speed and can monitor camshafts, crankshafts, transmissions, and other devices. There are 2-wire and 3-wire hall sensors. 3-wire ones are more flexible and accurate.

An illustration of magnetic field deflects in a battery

Hall effect sensors offer numerous benefits, such as much-needed reliability, high-speed operation, and pre-programmable electrical outputs and angles.

Users like it because of its ability to operate in various temperature ranges. They are widely used in mobile vehicles, automation equipment, marine handling equipment, agricultural machinery, slitting and rewinding machines, and process and packaging machines.

The failure of a hall sensor means that the controller, i.e., the board that powers and manages the motor, is missing critical information needed for proper synchronization of the motor’s power.

The motor receives power through three wires (phases). The three phases require proper synchronization; otherwise, the motor gets stuck, loses power, and makes an annoying sound.

If you suspect that your hall effect sensor is faulty, you can conduct a test with a multimeter.


Requirements and Safety

Requirements

We will test a Hall effect sensor using a multimeter, so that you will need a good multimeter (or voltmeter).

You might also need a jumper wire.

Optionally, you can conduct further tests using a Gauss meter and a signal voltage source, but this article only uses a multimeter.

Safety Precautions

Take the following safety precautions when testing a hall effect sensor using a multimeter:

  • Double-check the polarity when testing and reconnecting the hall effect sensor to ensure an accurate reading.
  • Optionally, wear protective gear (gloves and glasses) while handling the hall effect sensor.

Testing a Hall Effect Sensor with a Multimeter

The Hall effect sensor test described here can be applied to almost any Hall effect sensor in modern vehicles.

Note: The vehicle’s ignition must be switched on while testing the hall effect sensor; otherwise, you will get a zero reading. It needs a magnetic field to function; you must test it while it functions to test the operating voltage.

Step 1. Locate the Hall Effect Sensor

Firstly, you must know where the hall effect sensor is located.

Examine the engine’s schematic, if necessary, to locate the “camshaft sensor” or the “crankshaft position sensor” to the electronic control module (ECM). That will most likely be the Hall effect sensor.

A hall effect sensor
Video | TF Automotive

Step 2. Set the Multimeter

Set the multimeter to measure up to 20 volts DC if it’s an analog type.

Step 3: Attach the Probes

Attach the multimeter’s probes as back probes, as in the picture below, or touch one end of the jumper wire to the supply or signal wire and the other to the positive (red) probe’s tip.

The multimeter’s negative probe should touch a good chassis ground connection or the sensor’s ground pin. Consider using a jumper with alligator clips when connecting the negative probe to the chassis ground.

A hall effect sensor being tested
Video | TF Automotive

Connect the sensor’s signal wire to the multimeter’s input if you have a 3-wire hall effect sensor instead of a 2-wire one. A signal pin is common on wheel speed and distributor hall effect sensors.

Normally, in a 3-wire hall effect sensor, the two end pins are the supply and ground ones, whereas the middle pin is the signal one, but check the vehicle owner’s manual or sensor’s specifications to make sure.

As shown in the picture below, you can bring a metallic object near the hall effect sensor to turn the signal voltage on or off. This should work in a healthy sensor, but it’s only a quick test to see if it’s functioning normally. A more definitive way of testing the signal pin is to use an oscilloscope.

A person testing the signal pin on the hall effect sensor
Video | TF Automotive

Step 4. Check the Reading

To recap, connect the multimeter’s black probe to a ground connection, the hall sensor’s black terminal, and the red probe to its supply terminal directly or via a jumper wire.

Check the reading on the multimeter. It should be around 12-13 volts. The reading shown in the example below is 11.73 volts, which can be considered acceptable.

An acceptable Hall effect sensor voltage reading on a multimeter at 11.73
Video | TF Automotive


Summary Table and Troubleshooting

The table below summarizes the expected values.

Wire
(Sensor’s terminals)
Probe
(Multimeter’s probe to connect)
Voltage
Power supplyPositive (red)12-13 or 5 volts DC**
GroundNegative (black)0 volts DC
Signal*Positive (red)DC volts square wave
Testing a Hall effect sensor with a multimeter

* For wheel speed and distributor hall effect sensors

** The voltage reading to expect depends on the voltage supply to the vehicle.

A Hall effect sensor reading lower than expected at 4.27
A Hall effect sensor reading lower than expected

If the hall effect sensor fails to work properly, carefully disconnect and remove it from the engine block and clean it. Look out for dirt, metal shavings, and oil. If any of them are present, clean them out.

While handling a hall effect sensor:

  • Power off the vehicle or other device using the sensor when disconnecting it.
  • Handle a Hall Effect sensor carefully because its delicate semiconductor can easily get damaged if mishandled.

Reconnect and repeat the test after cleaning the hall effect sensor. If it still fails to work, you must replace it.


Resistance and Current Tests

You can also conduct resistance and current tests on a hall effect sensor.

Set the multimeter to measure ohms when testing resistance and amps when testing current.

Testing Resistance

Connect the multimeter’s red and black probes to the hall effect sensor’s power supply and ground pins. Compare the reading you get with the value range specified for the sensor.

Testing Current

Connect the multimeter in series with the sensor to test the current flow. Compare the direction indicated with that specified in the sensor’s datasheet.


Testing Other Hall Effect Sensors

Hall effect sensors are also found in other areas, such as motors and vehicles like scooters.

If they operate on 5V, you should expect a 5V or slightly higher voltage reading.

Procedure

Connect the multimeter’s black lead to the harness’ black wire and the red one to its green wire.

Check if the voltage reads five or more volts. Note that the voltage depends on the circuit input and could vary from one device to another. However, it should be greater than zero volts if the Hall Effect sensor is okay.

Move the magnet slowly at a right angle to the front of the position sensor and note what happens. The voltage should increase as you move toward the sensor and decrease as you move away from it. The crank sensor or its connections are faulty if there is no voltage change.

If the response is unclear, removing the hall effect sensor (while the engine is off) is best to test it using an oscilloscope instead.


FAQs

How Can You Tell If a Hall Effect Sensor is Faulty?

A faulty Hall effect sensor might give an inconsistent voltage reading, no reading, or a reading that doesn’t change in response to a magnetic field. Other signs include the motor or device connected to behaving erratically or not functioning at all.

What Should You Do if The Voltage Reading is Lower Than Expected?

If the voltage reading is lower than expected, ensure your multimeter functions properly and the sensor is clean and free from metal shavings or debris. If the problem persists, the sensor might need to be replaced.

Can You Test a Hall Effect Sensor without a Multimeter?

While a multimeter is the most common tool for testing a Hall effect sensor, you can also use an oscilloscope for a more detailed analysis of the sensor’s output. However, testing a Hall effect sensor without specialized tools is challenging.

Is It Safe To Test a Hall Effect Sensor on Your Own?

Testing a Hall effect sensor on your own is safe if you follow the proper safety protocols. Ensure the vehicle or device is powered off when connecting or disconnecting the sensor to avoid electrical hazards.

Are There Different Types of Hall Effect Sensors?

There are different Hall effect sensors, including 2-wire and 3-wire sensors. The testing method may vary slightly depending on the type, so always refer to the manufacturer’s guidelines for the specific sensor you are testing.

Do You Need to Take Any Precautions When Handling a Hall Effect Sensor?

Handling a Hall effect sensor with care is important to avoid damaging it. These sensors can be sensitive to static electricity and physical shocks. Always touch a grounded metal object to discharge static before handling the sensor, and avoid applying excessive force.


References

Website Resources:

TF Automotive

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About Sam Orlovsky

AvatarCertifications: B.E.E.
Education: University Of Denver - Electric Engineering
Lives In: Denver Colorado

Electrical engineering is my passion, and I’ve been in the industry for over 20 years. This gives me a unique ability to give you expert home improvement and DIY recommendations. I’m not only an electrician, but I also like machinery and anything to do with carpentry. One of my career paths started as a general handyman, so I also have a lot of experience with home improvement I love to share.

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