How to test a digital ABS wheel speed sensor

This case study is a good example of how my engine performance testing methods can easily be applied to other areas of the car, giving you confidence during diagnostics! This Chrysler 300 comes equipped with ‘digital’ ABS wheel speed sensors, which differ from conventional variable reluctance sensors, and are becoming more and more common on newer vehicles. Be sure to check the related videos below for more ABS sensor testing info.

Engine Performance Diagnostics chapter 2

Symptoms
- ABS/traction control lights on
- ABS codes 12 and 13 stored

Fix
- replace the right front ABS wheel speed sensor

Tests shown
- using graphed scan data to check for wheel speed sensor function
- using the Snap-On Troubleshooter to learn more about component testing
- how to scope test a digital ABS wheel speed sensor
- how to check if a sensor circuit is pull-up or pull-down by disconnecting the sensor
- how to perform a bypass test (pull-up or pull-down) on a sensor signal circuit
- understanding bypass test variables, including shorted sensors and setting trouble codes
- how to perform a visual inspection on a wheel speed sensor and tone wheel

Tools used
- Autel MS905 MaxiSys Mini Diagnostic System with Connector Kit - USA Version
- PicoScope 4425 4 Channel Standard Diagnostic Kit
- incandescent test light

Playlist
- ABS Wheel Speed Sensor and System Testing

Related videos
- How to test a digital ABS wheel speed sensor - 08 Chrysler,Dodge,Jeep
- Magneto Resistive ABS Wheel Speed Sensor Test - 2006 GM
- ABS activates on every stop - damaged tone ring
- How to test an ABS Wheel Speed Sensor (VRS type)

On ScannerDanner Premium I will bring you right into my classroom at Rosedale Technical College. You will find page for page lectures taken right from my book as well as exclusive classroom type case studies. What is so special about these classroom case studies? I pull live problem vehicles directly into my classroom and we troubleshoot them in real time, using and applying the theory and testing procedures we learn during the classroom lectures. There is no better on-line training of how to troubleshoot automotive electrical and electronics systems anywhere!

Disclaimer:
Due to factors beyond the control of ScannerDanner LLC, it cannot guarantee against unauthorized modifications of this information, or improper use of this information. ScannerDanner LLC assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. ScannerDanner LLC recommends safe practices when working with power tools, automotive lifts, lifting tools, jack stands, electrical equipment, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this video. Due to factors beyond the control of ScannerDanner LLC, no information contained in this video shall create any express or implied warranty or guarantee of any particular result. Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained in this video is the sole responsibility of the user and not ScannerDanner LLC.

[wthutmrcy]

For those who are concerned about running higher voltage to low-voltage circuits (like in this video), I have one question for you: When you open the fuse box in your car, do you have 10 volt fuses, 5 volt fuses? No. It's the amperage that burns the circuits, and since the test light has a limited current drawing bulb in it (I think the one he mainly uses, doesn't draw more than 200mA), there isn't enough amperage flow through the system to cause damage.

[ozzstars_cars]

Great explanation of the test procedure. My wife came home tonight from work and told me the abs/vdc light came on just before she got home. I'm going to the downstairs to the garage now ;-)

[ScannerDanner]

I think you are correct. This is not a "hall effect" design. Mitchell-On Demand describes this as an active wheel speed sensor with an integrated circuit inside the sensor. There is also mention that the computer looks for current and voltage changes on the signal wire

[mladenmilosavljevic]

Had a same type of faulty sensor on Fiat Stilo 2002. Your video helped me a lot, I'm used to those inductive, classic abs sensors. Thanks, best wishes from Serbia. :))

[ScannerDanner]

watch the video response from one of my friends here. He does an excellent job and will answer your question

[rjgrasmuck]

It's a well learned lesson. Don't forget the basics. And I'm glad I learned this hard lesson on my car at home and not on a customers car.
I graduate from UTI Sacramento next August and from there hope to do a manufacturer specific advanced training. I try to watch at least one of your videos a day. I have learned so much! I can't wait to get your book when I get some extra dough. Don't feel bad for laughing. I laughed too.

[andyfanshawe]

Whenever I get an email notifying me of a new scannerdanner video I get quite excited!! No, I've not got a sad life (well, ....). As usual brilliant Paul. You must seriously enjoy your job.

[lucho]

Your videos are great, learned a whole lot in just 2 videos. Will definitely subscibe and follow!

[mike-ypuk]

there are lots of different people showing how to videos but they dont give any depth of understanding and that can create room for error.you have this down to a science. the material is so packed with information and reviews are a must to get it into memory.your book is the greatest in my collection. keep it up this is better than dealership training. i like field videos without schematics because it show how to real time diag. great video

[laurentpk]

Excellent tutorial. Well done. Very informative. Thank you for posting.

[nestorfresno]

awesome video Paul, I learn something new from each your video, thanks for sharing ..
never thought of bypassing the signal wire .. good info!!!

[whitetiger]

Great video Paul. A lot of great information.

[ScannerDanner]

RJ
I am still laughing. I am so sorry for your trouble my friend. It really is kind of funny though isn't it? I feel bad for laughing

[cappaculla]

Yep, this channel has what I needed, I kid you not some youtube guy Scotty Kilmer said to, ignore and or take out the ABS fuse.. I kid you not...

[rjgrasmuck]

So, I looked at my car the other day and noticed that I didn't have an ABS light illuminated during the bulb check when first turning the key ignition on. I decided I was going to find the problem ensuring that all the wiring was sound and that the bulb was in fact the source of the problem. I was inspired by Mr. Danner. I did a ton of research, found wiring diagrams for my car and after completely tearing the dash apart, I found out why the ABS light didn't work...
I don't have ABS! :(

[nestorfresno]

good way to explain the pull up, pull down design sensor type voltages, good to know thet way you can bypass pretty much any type of sensor to check the circuit going to the pcm..goo video Paul

[ScannerDanner]

Thanks Hank!
It is such a valuable tool, isn't it? I am always looking for ways to "create a signal and look for a response"
Speed and accuracy is what this type of testing provides. Don't you think?

[jHuff-dmlz]

Very Nice Video Mr.DannerScanner

For those, like me, that dread the idea of pumping 12v into an ECM there is the Voltage-gate. It uses a 12 ohm and 3 ohm resister to pull the voltage down to 3 volts. Ask any electrical guy and they'll build you one.

[Sam-dele]

Fantastic Presentation.  Totally Awesome!!!

[ScannerDanner]

use at least a 5k ohm resistor. this will protect the reference circuit from an accidental short to ground. doesn't matter resistor size as there will be no measurable amount of current flow so heat is a non issue