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Honda Magneto Resistive Wheel Speed Sensor Testing Using Autologic’s DrivePRO

Antilock brake wheel speed sensor testing

In this video and article a faulty wheel speed sensor (WSS) on a Honda vehicle is tested. Two methods are used. First using Autologic's DrivePRO Asian diagnostic software and the built-in pulser test. Then, confirmation of the signal is checked using a Pico Scope.

Autologic DrivePRO Asian diagnostic software for Honda vehicle has a built-in function test for antilock brake wheel speed sensor testing. This test can speed the diagnosis of a possible faulty wheel speed sensor with a non –intrusive test method

Begin by identifying the vehicle you are working on

Turn the key ON with the engine OFF

Select Done

Select Detect Automatically VIN Read

Select Enhanced Powertrain

Select Brakes

Select Antilock brakes

Read and Understand Warning

Select OK

Select Service Functions

Select Tests

Select Pulser Test

Select Start

Select Back > (greater than) and Next < (less than) buttons to select the wheel you wish to perform the Pulser test on

In this example, we will select the Left Front Wheel

Select Done

Read and understand instructions on screen

List and safely support the front axle of the vehicle so both wheel spin freely

Engine OFF, Transmission in Neutral and Parking Brake Released

Select Next

Put a piece of masking tape on the upper most part of tire. Center top

Select Next

Rotate wheel slowly and stop when the counter value is 1

Mark the fender using masking tape at the location of the masking tape on tire

Select Next

Rotate wheel opposite direction and stop when the counter value is 3

Mark the fender using masking tape at the location of the masking tape on tire

Select Next

The position in the middle of the tape positions 1 and 2 is the start position

Align the tape on the tire with the start position

Mark fender at start position with tape

Select Next

Rotate wheel one full revolution and stop at start position

Record target Pulse Counter value and Pulse counter value

Select Next

Test is Complete

Target pulse value and Pulse value should match

If the values do not match, there could be foreign material on or near the sensor tip or a faulty sensor

Our subject vehicle does not match

With a fault in the sensor signal confirmed using diagnostic software, the sensor signal can be tested using a scope

Our subject vehicle, 2009 Honda Accord is equipped with magneto resistive wheel speed sensors. These sensors produce a digital signal

A functional sensor should produce a signal as shown. A digital square wave ranging from about 10 volts to 11.5 volts DC. The signal should begin to generate as soon as the wheel is moved from a stop

On our subject vehicle with the faulty sensor, the digital signal drops out for long periods of time during wheel rotation. As indicated here