How to check the ABS sensor with a multimeter (manual)

Content

When to Check the ABS Sensor
What you need to have when checking the ABS sensor
How to Test an ABS Sensor: Get a Reading
Protective gear
Summing up

ABS (anti-lock brake sensor) is a tachometer that measures wheel speed. It then sends the calculated RPM to the Engine Control Module (ECM). ABS is also known as wheel speed sensor or ABS braking sensor. Each wheel of the car has its own speed of rotation, the ABS sensor captures these speed indicators.

After receiving wheel speed reports, the ECM determines the lock state for each wheel. Sudden screeching when braking is caused by the ECM locking up.

If your vehicle's ABS is malfunctioning, you may lose electronic stability and traction control. Thus, it is dangerous to drive a car without knowing the status of the ABS sensor.

Check the ABS sensor if the traction and sensor indicator lights up on the car's dashboard.

In general, to test the ABS sensor, you need to install multimeter leads on the electrical connectors. You then need to spin the car's wheels to get a voltage reading. If there is no reading, then your ABS sensor is either open or dead.

I will go into more detail in our article below.

ABS sensors are among the most commonly used sensors in automobiles. In the new brake system, the ABS is located in the wheel hub. In a traditional brake system, it is located outside the wheel hub - in the steering knuckle. It is connected to a ring gear mounted on a broken rotor. (1)

When to Check the ABS Sensor

The sensors and the traction control system light up when the ABS sensor detects a malfunction. You should watch for these sensor malfunction indicators on the dashboard while driving. The traction lamp is conveniently located on the dashboard. (2)

What you need to have when checking the ABS sensor

Digital multimeter
Clamps (optional, you only use sensors)
Tire jacks
ABS reading kit to help you read ABS codes and know which one needs to be replaced
Wrench
Floor carpets
Brake installation tools
Ramps
Charger

I prefer digital multimeters because they just display values or readings on the screen. Analog uses pointers, so you'll need to do some calculations.

How to Test an ABS Sensor: Get a Reading

The multimeter consists of three main parts, namely the display, the selection knob, and the ports. The display will often show 3 digits and negative values may also be shown.

Turn the selection knob to select the unit you want to measure. It can be current, voltage or resistance.

The multimeter has 2 probes connected to its ports labeled COM and MAV.

COM is often black and connected to circuit ground.

The MAV resistance probe may be red and connected to the current reading.

Follow these simple steps to test all ABS sensors with a multimeter. Be sure to check the manual to see how many wheels the ABS sensor is on and check all sensors.

Pay attention to their standard value in Ohms.

Here are the steps:

Park your vehicle and make sure the transmission is in Park or Neutral. before turning off the engine. Then set the emergency brakes.
Use a jack to raise the wheel next to the sensor you want to test. Before that, it is better to spread a rug on the floor under the machine, on which you can lie down, and it is convenient to carry out repair work. Don't forget to wear protective gear.
Disconnect the ABS sensor from the connecting wires by safely removing its cover. Then clean it with brake cleaner (the sensor is canister shaped and has connecting wires).
Set the multimeter to ohms. Simply but firmly adjust the knob to point to the ohm setting. Ohm or resistance is denoted by the symbol "Ohm".
Set the multimeter to display zero by steadily turning the zero adjustment knob.
Put the probe wires on the contacts of the ABS sensor. Since the resistance is not directional, it doesn't matter which end you put on each probe. But keep them as far away as possible to get the right reading. Wait to get the agreed value.
Pay attention to the readings Ohm. Compare it to your sensor's standard ohm value from the manual. The difference must be less than 10%. Otherwise, you must replace the ABS sensor.

Alternatively, you can set the multimeter to measure voltage (AC).

Connect the test leads to the ABS sensor and turn the wheel to get a voltage reading.

If there is no value on the multimeter display, then the ABS is faulty. Replace it.

Protective gear

You have to interact a lot with lubrication and heat. So, gloves prevent oil from getting on the nails. Thick gloves will protect your hands from burns and cuts from items such as wrenches and jacks.

You will also be tapping with a hammer. In this case, many particles will explode into the air. Therefore, it is important to have eye protection. you can use screen protector or smart glasses.

Summing up

For safe driving, it is important to monitor the condition of the ABS sensor. Now we know that: the appearance of a pull and sensor indicator on the dashboard, as well as the absence of readings on the panel of the multimeter, means that the ABS sensor is faulty. But sometimes you can get multimeter readings, but still the sensor pull and light are saved. In this case, you will need the help of a technical specialist.

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