Magneto Resistive ABS Wheel Speed Sensor Test - 2006 GM

In this video we are working on a 2006 Chevy Colorado with a left front wheel speed sensor code. This is a digital type wheel speed sensor, so testing methods vary from the standard VR sensor.
For more information on this topic, I have written a “field manual” called Engine Performance Diagnostics which is available at www.scannerdanner.com as an eBook or paper book.
Want even more diagnostic training? Whether you are a DIY trying to fix your own car, someone looking to become an auto technician, or a current auto technician that wants to get more into diagnostics, subscribe to ScannerDanner Premium www.scannerdan... There is a 14 day free trial.
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.

[@ScannerDanner]

Agree 100% about the voltage level being different on a different car. IT also will matter what test light you are using. I have used an incandescent light many times but I like the LED light here much more. Better to be safe than sorry.

[@bbmd2200]

Love this video because it allows me to see how using an LED test light can be a good thing and can sometimes get you in trouble. I have been thinking of buying one, but have not been able to do that because I usually use a DVOM or an incandescent test light. Especially, after watching one of your most recent videos, where you used the ohmmeter and the diode function to inject a small voltage into the signal wire to check for signal wiring integrity. Wish you and your family a happy new year! Please, Keep Haiti in your prayer. Only Divine intervention can help us out of the mess that we are in.

[@Mikesky10]

hyundai uses this type of sensor as theres speed wheels sensors, the problem is that when there is any malfunction on it circuit the computer sets a DTC and stops sending the 12 v to feed the sensor inmediatly, but you can see a 12v pulse before it detects a failure in the circuit a stops feeding the sensors, and to check the signal/ground wire do a by pass test like you show in this video!!!, thank you for teaching so much Paul!!!, amazing as always!!!!

[@plupkination]

Whoa wait! I have been going nuts with my 2006 Hyundai sonata GLS's ABS system, and this video is the most similar situation to what I have.. I recently had a driver's side front axle replaced after a catastrophic ball joint failure (wheel almost fell off), after which my ABS as well as my ESC lights both came on (already checked sensor lead integrity, it is still good).. So what you are saying is that if the mechanic maybe disconnected the sensor with the ignition on, or if the sensor came unplugged during the ball joint failure, that the car's computer stops sending the feed voltage to the sensors?!??! How do you reset this??! PLEAAASEE!!!! Should it just reset after turning the ignition off/on? Or is this something more complicated to reset?? PLEAAASE HELP!!

[@fuckjewtube69]

This is still valid and solid information.

[@michaelgalvin1024]

Great, I remember this one, it was when you started using smooth introduction pictures/ images. Nice one, thankyou. Mike Galvin

[@ScannerDanner]

I think you are addressing one of my questions in the video. What I didn't know was what the resistor value was inside of the computer on the signal circuit. Not that it matters, I was just trying to explain to some why we did not have a complete 12v drop across the LED light when connected to the signal circuit.

[@ScannerDannerPremium]

I did, it is in the video itself. Make sure you do not turn the captions off when you watch my videos. Thanks!

[@adishajrovic2082]

Here is a another GOLD MINE video made by Mr. Danner also very good videos and explanations, very easy and simple to understand.

[@victor35ma]

I'll show you how you can test this sensor and the abs ring in one min or less: using a Pistol grip style soldering gun removed tip. The soldering gun connected to power(110 acv) it creates a lot magnetic waves then place the gun as close as you can to the sensor then watching the scanner abs PID specific for that wheel you will see the sensor inputting a lot volt to ABS Module. That’s suggesting good sensor and wiring. Thanks Scanner Danner for another super good lesson appreciated

[@masksareforwhitepeopleonly4311]

feeling thankful for all the info you already put out there for free thanks, in no way do I feel pintle humped 10 bucks a month thats a deal bro

[@Caradonia]

Just to back up your point on the L.E.D test lights, I just carried out a quick experiment. I've got a very well known brand of test light that was expensive for what it does. At 12.6v this test light carries 14mA of current. Using a 5.1kOhm resistor in series (5100ohms) on the ground side of the resistor, this thing still lights up! This is last thing I'd rely on for finding ground faults that's for sure!

[@ScannerDanner]

Nice! Thank you for that. That gives me an idea for a video. Open and short circuit testing with a test light using both LED and incandescent lights.

[@Jay-vi7el]

Great explanation between led and non condesent test light

[@gvvq-pi5ml]

Hi Paul, you are right of course, I didn't think about the absence of an earth wire so not a hall effect chip, and yes about the switching so obviously not the reluctor or gap..cheers - Fred.

[@PompeyMatt17]

10:49 on plastic "pull down" sensors the ground is the brass ferrule where the fixing bolt goes through, inside is an earth wire to the sensor

[@plowe6751]

17:52 This explains why when voltage drop testing computer ground during cranking, the voltage measurement can go up to 200 or 300 millivolts. It's because the starter has low resistance and the voltage drop across it is lower too, resulting in some voltage left over on the ground side of the starter.

[@ScannerDanner]

Think of it as the block being pressurized from a massive amount of current. This causes block voltage to rise and literally everything else that is connected to the block

[@ScannerDanner]

Also, you are correct in that any time we call a bad ABS sensor we should always verify air gap and check for a cracked tone ring (this is not possible on the units that are combined with the wheel bearing assembly). In our case I do not believe that was necessary. Remember the voltage levels? .6 with it low and 1.8 with it high? We had a flat line 0v signal. I do not believe an air gap problem would cause that. The signal could be fixed, but not at 0 on this design.

[@vasiavisilievic1873]

As an alternative, you could just swap the wires on left and right sensors, to find out if the sensor or the wiring is bad. Can't think why this method wouldn't work.

[@estrelladelnorte1308]

thank you , you know we really enjoy your channel sr , and we apretiate what you do for us , you have no idea how much i have learned from you, thanks for being who you are .

[@ElectronicWorkshop]

your explaination of the test methods to verify the workings of the circuit is very clear, i only wish i could be as clear as you I was describing the inside electronics of a simple LED Light your right about the resister inside the computor, all you need to know is its a high value resister. Keep up the good work, the videos are great

[@ScannerDanner]

The computer and it does monitor the feed side too. At least for opens and shorts. I am not sure how much on this design that it is "watching" the feed voltage for signal interpretation. I did prove that the signal is monitored on the other wire though right? You will see in my next upload, that this changes. That on some it is the feed side that is monitored for a signal. And again, I know that current is also monitored on these too but that doesn't change our diagnostic approach.

[@user-wd1rj6sb5l]

I think that the design is an internal resistance in the PCM connected to the ground inside, let us assume its value (1 k ) ohms, and the positive line coming out of the PCM is 11.6 volt , and the sensor is two resistors whose values, let us assume (3.87 K ) and ( 6.73 K ) ohms, are connected in series and fed to the source ( 11.6 Volt ), One of the two resistors ( 3.87 k) is connected in parallel with a transistor that connects and disconnects with the rotation of the wheel. When the transistor connects, it will cancel the resistance ( 3.87 k ) ohms , and thus the internal resistance of the PCM, which is 1 kilo ohm, will become connected in series with the resistance (6.73 k) and thus the voltages on the PCM pin will be ( 1.5 volt ) But when the transistor is cut off, the three resistors become connected in series, and thus the voltage becomes ( 1.5 volt ) volts , this is my think

[@malondc1]

The premium is worth gold im subscribing right now. i already bought the ebook and the video lectures 13,14 and 15 thanks paul this is great

[@ScannerDanner]

In our case I do not believe an air gap could be the problem. Remember the voltage levels? .6 with it low and 1.8 with it high? We had a flat line 0v signal. I do not believe an air gap problem would cause that. The signal could be fixed, but not at 0 on this design. But I agree, a visual is always in order when testing ABS sensors.

[@ElectronicWorkshop]

great video Dan LED circuit design have a high value resister to limit current in the led, this resister is determined by the current rating of the light emitting diode, the led has a voltage drop of between 1.8v and 3.3v. depending on the type of led, you can find the value of the current limiting resister if you know the led voltage drop and led current rating

[@Caradonia]

Great video again, Paul. Thanks! A simple way to explain the test light lighting is simply two resistors in series. The L.E.D being one of them and likely to be around 900ohms, which will leave very little for the computer resistor.

[@nickayivor8432]

KNOWLEDGEABLE Sir ScannerDanner Good Morning 🙏 🌄 Take care and have a great day 👍 Tutorial helpful video Sir ScannerDanner From Nick Ayivor from London England UK 🇬🇧

[@kingbodetailthebestornothi9997]

Excellent!

[@ScannerDannerPremium]

An air gap issue is always a concern, but in this case an air gap issue would not have caused a 0v signal all the time. A good visual inspection should always be done though for sure.

[@JOHNPHUFNAGEL]

Paul great video in the part of this video when you said "How does the computer know when there is a wheel lock up" I was under the impression that it compared the signal between the lock up wheel and the other 3

[@bwdz75]

One thing to add is that on the Colorado they are famous for throwing a code on the incorrect sensor. Also the design of the brakes makes it very easy to damage the bearing magnetic ring or -/+ ring if that's what they're called when removing or replacing the rotors and it is difficult to re use the sensor and sensor holder with the correct gap particularly when rusty

[@kerdainkelly8740]

Living legend and great teacher

[@ScannerDanner]

It's probably because my theories of the workings of the computer signal circuit are not accurate. I know that is also measures current but in my opinion measuring sensor Miiliamp draw is not necessary in this particular case as I will show in the next upload.

[@plowe6751]

On an ABS system without bias voltage, you could disconnect both front sensors and connect the left front connector to the right front sensor with very long wires. If the scan tool shows a good signal for the left front sensor (that is actually the right front sensor), then you know the left front sensor is bad.

[@ScannerDanner]

I prefer using my test light to trigger the circuit. It's much easier

[@7minnow]

You Da Man SD

[@ScannerDanner]

What are you said about? I am not changing anything I do on this channel. Just moving all of my classroom lectures and future live events to a paid subscription channel. It will be way cheaper than what I am charging for the lecture videos now and as long as you are a subscriber the videos never expire.

[@everardocamacho5063]

Thank you paul,

[@ScannerDannerPremium]

Thanks man, and I really value your contributions as well. You have much to offer yourself.

[@ScannerDanner]

Hopefully soon. Got a lot on my plate

[@ScannerDannerPremium]

Thank you so much. I promise to uphold my end of the bargain.

[@andyamanda5777]

You are genius ! Well done, im very impressed.

[@7minnow]

Mr Paul, can’t find your friend on the LED on the internal design of the testlights Thanks SD the Best

[@Mummyy84]

Still great video the led ligth volt testing was new to me. Thanks :)

[@mctobbsi]

If I may add something about voltage drop over resistors. The resistor in the circuit doesn't need to hade a high resistance to do a big voltage drop. Example: 2 resistors, 50 Ohms and 10 Ohms will lead to a 10V drop over the 50 Ohm and 2V over the 10Ohm. The same goes for higher resistance. I.e if we hade a 5KOhm resistor and 1KOhm the drop would be the same as above. The total resistance value in the circuit decides what the drop would be over every resistor.

[@ScannerDanner]

That is part of it too for sure. I never meant to imply that it wasn't watching the other wheel and other inputs. Sorry about that.

[@sunnypatel1524]

Sir you said in the video that you will leave a link to somebody's video. The video in that explains internal cuircit of speed sensor. But, I did not find that link

[@ScannerDanner]

In the workings now my friend. Probably in a few weeks.

[@vencentbauer]

nice video Paul I learned a lot on tgat 1

[@flapbean]

Great video, thank you. What should I be looking for in the service manual as to what tolerances are acceptable? Cheers

[@jorgeboyas2255]

I really like the led test light test for checking to see if the computer is bad. I'm really not that comfortable using the test light to do this test because I really do not think I'm ready to take short cuts just yet and I'd hate my self if I burn out a computer. But I see using a test like and checking for power in the signal wire just eliminates and what a flow chart will tell me to do for checking for continuity at the abs sensor connector and the computer connector. Overall, thank you for the video and keep up the great work with the training for all of us technicians.

[@ScannerDanner]

You would really like my chapter 3 material on SD Premium. There is a 14 day free trial and you can subscribe here www.scannerdanner.com/join-scannerdanner-premium.html I think after watching these lectures and case studies you will feel a lot more comfortable with this type of testing. Thanks! Hope to see you there.

[@steveguest8028]

Great video Paul thank you 👍

[@Mummyy84]

Paul 26:50 You still could have bad ring in axle(drive shaft) or bad magnetig ring in bearing debending what type it is. OR too big airgap betwean sensor and object that its scaning.

[@AutoDiag_]

Would you recommend led test light for sensor bypass wiring integrity and to see live data change? Or it is safe with normal bulb that draws around 120ma.

[@ScannerDanner]

On this type of sensor circuit, absolutely.

[@Mummyy84]

You are rigth 0.5v is teached to me be the low volt to pcm know is sensor borck or not. so yeah flat 0v makes it kind asure to be sensor. In realife, i make sure to my go workers, look them anyway to be sure not to only trust meters. because we service all cars and if some year or model sudenly its normal and there is simple ring missing, oh boy they get in "Sauna", if they change sensor anyway ;)

[@jarredtoms9637]

Good video, the only thing i would comment on is (and please correct me if im wrong) but by not using a wiring diagram you could in theory have the 2 wires round the wrong way on the abs plug (unlikely, but still very possible if a vehicle had a wiring repair or a new incorrect harness for example) im not sure what effect this would have on the system, but my guess would be a good power feed but missing or incorrect voltage out, which would lead you to replace the sensor or look for mechanical defects.

[@Caradonia]

Look forward to it. Your book ebook is great by the way. Highly recommend it to anyone thinking of buying it.

[@mikeczuba4349]

this is a hall effect type 2 wire instead of 3 there is a resistor in the module signal side the hall effect changes the current typ. 7 - 14 mA magneto resistive magnet in sensor ferrous reluctor some use the magnetic target wheel looks like a hub seal some sensors are directional detecting 3 hall chips and circuitry in sensor still 2 wire produces three different signals stationary, forward and reverse

[@gvvq-pi5ml]

Hi Paul i believe most LED's use 20 to 30 mA, except the 12 volts ones, i don't know about those, from Fred in UK

[@all-about-programming]

You the best......

[@miltonscornertobylove5068]

I sure did learn something! Aweson video.

[@ScannerDanner]

+Milton Solis thanks for watching Milton!

[@abbeyrham4220]

always good quality information, thank you Paul. could u please do a video on the AC type sensors too.

[@jHuff-dm7lz]

Yes, very good video. As always.

[@twiggy04072]

The voltage levels you measured indicates there is a 100 ohm sense resistor in the signal side of the computer because that sensor is designed to switch between 7 and 14mA. Just wondering if you tried to measure that resistance with power off.

[@ozzstars_cars]

informative, thanks again Paul

[@rontownsend8235]

Like he just said, before it goes to ground. There are all kinds of grounds in these systems,just little wires bolted down to the main body works somewhere,if they are not making a good ground because of years of corrosion then you may have a simple problem there, so take it a part, xclean, dielectic grease and put it back together and move on. Do Not use led test light!

[@99rattle]

Nice explanation on the testing speed sensor. One question wouldn't the sensor air gap be a factor to the problem shown as well ,due to corrosion & mislead you to replace sensor ??

[@danielgromala5084]

mr danner looking for your friends vidio on internals at one time it was posted cant find it use what i have often in class he did an outstanding job on explaining mag res circuit can u direct me to that vidio

[@randy1ization]

when troubleshooting my 2000 bmw z3 with key on. the front wheel sensors have 3 wires, and one one wire shows 2.40 vdc, and the other (signal wire) shows nothing when spinning the wheel. the rear sensors have 2 wires, and generate a small a/c voltage when spinning the wheel.. the left side does, but right side doesnt.

[@mctobbsi]

Using the LED test light on another car may not produce the same voltage as on this car because the internal resistor to the computer is probably chosen with care for the specific wheel speed sensor used here. In this particular case the internal resistance of the computer probably ain't that high if we get a about 10V voltage drop with the test light. With that in mind I really would not use a incandescent light on a digital wheel speed senssor system. Someone please correct me if I am wrong.

[@TRcustomengineering]

Thanks again for another awesome video!

[@MitchMartinEngineer]

Good stuff Paul! Keep doin what you're doin!

[@trublue2319]

Great video

[@pierrebrunet1529]

mercedez uses this type of sensor ,is there a difference in voltage fluctuation on the negative side of the wire

[@jonka1]

@20:18 I always thought that the computer compared wheel speeds to detect full or partial lockup. Surely to make decisions on individual rate of change is going to take more computing power at the same time as it's monitoring the other wheels. Or am I wrong? Great channel I've just found you. Subscribed.

[@ScannerDannerPremium]

Thank you!

[@gvvq-pi5ml]

Hi Paul I would have called this a Hall effect chip no?, seem to behave like one to me, objectively as one of the other comment said, could have been reluctor or the air gap, always one isn't there :-) , good video all the same.....Fred in England

[@maximobautista4854]

great video. thanks.

[@ScannerDanner]

No ground on this sensor Fred. I thought these were hall effects initially too. Did you watch the video that I hyperlinked about these sensors from a fellow KZbinr?

[@kdautomotive1165]

Can you post that link it doesn't pop up as a hyper link for me

[@randy1ization]

I think my front sensors are active sensors because it has 3 wires and a 2.40 supply voltage from the computer with the key on . when I put my meter on the signal wire with the connector plugged in, via backprobe, and spin the wheel, what voltage should I get ,, does the speed sensor interrupt that 2.40 supply voltage and become an on/off signal to the computer? nothing is happening, and im wondering if my digital VOM cant pick up the dropout voltage?

[@anthonybrownsr8764]

What type of obd two scanner that show you which wheel speed sensor is bad?

[@4YouWHOyou]

Can i do that test with regular test light ?

[@fivefortyeye540i]

In what cases would this test not be valuable in on a input circuit

[@grzegorz16100]

I wish I could understand. I have to watch it again...

[@Rex-tf1xm]

Sir Paul where's the link you tell that you saw a video of one from your friends drawing a internal diagram of wss?

[@ScannerDanner]

If it's not in the description or comments, I'm not sure

[@vicky-nc3to]

I am checking a ferrari 575 M, There is a fault related to ABS system, C-1202. I checked all the speed sensor value with tester & come to know that rear right speed sensor value does not changes while driving. Ok it could be a speed sensor problem, but this fault is not getting erased while the car is stopped/ idle. I guess it should be erased while it is ignition on condition. Any idea about that ?

[@kruno45]

Stupid question I have a ford explorer I'm working on what if a bearing for a passive system was accidentally installed on a active abs system?

[@redsson6669]

great video as always, are you gonna be making part2 of the picoscope training?

[@AAA-br3cs]

Why not bais voltage on signal line?

[@Mikesky10]

hi Paul, watching this video, and knowing about tension drops, to do the by pass test for this type of sensor, im guessing that i could also use any high cheap resistor, lets say 700 to 900 ohms, watch the 1.4 v aprox. and generate the signal by touching the wire the same way you did with the LED light; is that correct?????, by that way I LOVE THE BY PASS TEST!!!!!, is awesome, thank you for teaching that test!!!!

[@ScannerDanner]

Yep. That should work. Thank you!

[@Mikesky10]

ScannerDanner what if i use a triple A battery, the ones that you remote control of your tv uses, connect it directly to the signal wire and do the by_pass test?

[@ScannerDanner]

sure, but you'll need to ground the other end of the battery to the car.

[@Mikesky10]

ScannerDanner of course!, thank you!; but i wonder, how to do the by pass test in the 2008 commander wss, the one that changes the voltage betwen 10.4v and 10.8 i belive; i have not figure it out how to simulate that small drop in the voltage to test the reaction of the module and test circuit wire!

[@chromeharris]

Where is the LED test light video, also what size of T-pins do you recommend?

[@JDMCARSCIVIC]

How would you test the jeep commander type sensor?

[@ScannerDanner]

I have a video on a Dodge using this type of sensor, I'm sure it is the same as your Jeep

[@ScannerDannerPremium]

lol on the pintle humped Thanks!

[@lucianoecco1690]

how to test a feed 0v if a short to ground in a pull down design abs sensor thanks

[@tharindutest9930]

Bad English. Try again.

[@everardocamacho5063]

Hi paul my Buick regal 2002 3.8 has a abs code c1214, check all fuses they are ok, the abs ligth can be cleared what's the problems thank you paul cheers from ontario ca, I like to watch yours videos

[@ScannerDanner]

You need to get your hands on a c1214 flow chart and get a good wiring diagram. My forum would be a good place to start. www.scannerdanner.com

[@gypsysharky]

This did not work, is the computer shutting off bypass signal? i tried on both sides with LED test light and reset fault but no signal??

[@ScannerDanner]

Do you mean the bypass test? When it doesn't work :-) The next upload on the 2008 Jeep WSS, it doesn't work!

[@aliakas1402]

how abs controller know abs sensor is faulty the same time the wheel is not turnning around . scanner shows abs sensor code once i put the key on

[@HAm-ru8qk]

imo because of lack of small current feeding of bias voltage

[@mototechno834]

Hi Paul..Considering the cars with abs system, does the speedometer work with the help of wheel speed sensors??? I mean are these sensors responsible for the speedometer needle to spin?? Plzzz suggest. Thank you.

[@ScannerDanner]

Some cars, yes

[@rogerpatrick3642]

Hey scanner Danner I have a question could you unplug it and provide 12 volts on the other side and then see if the other side has a signal that comes out if so that would tell you if the ABS is good or not yes or no just a question you know more about that than I would

[@ScannerDanner]

Not all of the ABS sensors operate like this one, so there is no blanket test you can apply. What I showed on this model may not work on another one.

[@BlackBlade0001]

Would a Power Probe 3 be safe to use as a LED test light, in place of the one you used for this test? I couldn't find what its input impedance is.

[@ScannerDanner]

+Chris C yes, just don't push the button :)