DIY Wheel Speed Sensor Diagnostics

Case study of a 2002 Ford Explorer with wheel speed sensor codes C1155 and C1233 diagnosed by a Do-It -Yourselfer.

[@chohwoefebomo3133]

Merry Christmas folks... All thanks to God for His goodness and mercies throughout the year 2020. Thanks Matt. I've learnt a lot from you these 4months. Thanks Howard for the scope gift.

[@leesharp8039]

@Schrodingers Box just want to say a sincere thank you for the diagnostic knowledge you share here on youtube for free. I first discovered your channel in 2013 or 2014 when my 2001 S-10 was running horribly yet showed no DTCs & I had no idea what was wrong. My first instinct at the time was...you guessed it...to replace the plugs and wires, which would have done nothing. What I learned from watching your videos back then (especially the Diagnosis & Understanding Fuel Trims series) helped me diagnose the problem & get the truck back in tiptop shape without throwing parts at it until something worked. After successfully diagnosing & fixing my truck I started watching every video you published and taking notes like I was back in school. The things I have learned since then from watching you and a couple other youtubers (Scanner Danner & Eric The Car Guy) have helped me to become a pretty good diagnostician and save myself, my friends, & my family a boat load of money.

[@SchrodingersBox]

What a great Christmas story!!!

[@billyr9840]

Nice ! Almost thru you for a loop, but you were having no part of that ! Matt, Vicky and you have a Merry Christmas .

[@legallass9905]

Thank you. Merry Christmas!

[@SchrodingersBox]

Same to you! and thanks for the many years of support Billy!!

[@Honky_Konky_Phooey]

Merry Christmas to you and your family, all the best for 2021 👍

[@DependableAutoTruck]

i am so glad you got it figured out i might could have if i had known more about scopes in general but thats life hope it serves you will my friend

[@SchrodingersBox]

Thanks Howard!!! As you see it works great but I have to admit so still prefer the vantage lol!! I’ll definitely use it when I need more than 2 channels though! Thanks again my friend!!

[@satarosman5928]

Very informative, I learned a lot from your lectures. Thanks

[@SchrodingersBox]

Glad to hear that!

[@Silverfang15]

Had the old video open in an old tab and just went to watch it to find it removed! Glad I checked again to see that it was reuploaded.

[@SchrodingersBox]

Yea my apologies- I discovered an editing error where the second half was missing so I had to re edit and re-upload.

[@8953147]

That's a neat tool by Hantek, I like it Matt! Great discussion on inductive and digital sensors, and glad you figured the left side was previously installed with the wrong part.

[@SchrodingersBox]

Glad you liked it Jake! Happy new year!!

[@labradormcgraw]

Great video, Matt. I learned a lot from this. I think it was the photo-quality artwork that really clinched the deal - haha. I'm sure you're looking forward to being able to utilize four-channel diagnostics with the new scope. It certainly opens up new possibilities. I can't wait to see what new videos are in store for the new year.

[@SchrodingersBox]

Awesome, thank you! Got a surprise coming for you in about an hour.... keep watching!!

[@doubledensity2]

Awesome video! Thanks Howard!!!

[@mrweisu]

Great video! I'm just surprised that you were able to take both old sensors out intact and seemingly without a lot of trouble 😂

[@SchrodingersBox]

You and me both! I definitely have my moments. The last one I did I had to drill it out :-/

[@roxanneabbott8424]

I'm impressed how you think!! Thank you!

[@SchrodingersBox]

There is actually only one way to think. Anything else isn’t actually thinking. Think about it....

[@joejoebus8814]

First timer watching your videos and I must say that I like it. Good video and ThX. I will check out your others. And almost forgot, awesome new toy you have. Looks complicated but does many things. Wow.

[@SchrodingersBox]

Welcome aboard!!

[@Viper81766]

Hope you have a safe and blessed Christmas brother .

[@SchrodingersBox]

You too my friend!!

[@salvadorgutierrezr5914]

Thanks for teaching Mat and merry Christmas🙏👍👍👍👍👍👍👍👍👍👍

[@SchrodingersBox]

My pleasure!

[@jgeorges3061]

as always Matt, awesome information and MERRY CHRISTMASS my brother. cheeeers

[@SchrodingersBox]

Same to you my friend!! thanks for your many years of support!!

[@rickrogers2649]

I had a 2002 Explorer and put 2 Timken hubs on it. There was never a listing for more than 1 part number and I always check the manufacturer and several other listings. Guess I just got lucky. Sometimes ignorance is bliss I guess. Great video. I would love to own a scope someday. As for your artistic ability I think some of the drawings in this video looked a lot like some in the Covid videos. : ) Thanks again and Merry Christmas Matt.

[@SchrodingersBox]

Very nice!! Thanks for watching and I hope you get a scope soon!!

[@p121auto7]

Well done my master

[@stephenkareri9476]

Very helpful information

[@Ted_E_Bear]

Great video today !

[@SchrodingersBox]

Glad you liked it!

[@Pablo_Automotive]

Nice video again Matt I hope your enjoy fot you and your family at christmas a big hug from Spain ✨😊🛠

[@SchrodingersBox]

Thank you! You too my friend from spain!!

[@claudioparrenas652]

your the best boss!!

[@madds6678]

Nearly got caught out on a 2 wire sensor myself last week, I automatically assumed it’s not digital even after consulting a wiring diagram showing it had a 12v feed, my thought was nah digital 5v luckily when I hooked up a scope to a good sensor surprise surprise a digital signal 🤭. Interestingly I was going to check the resistance of the coil first but have since read on picoscopes site that you can damage a digital 2 wire sensor if you do that 🙄 Happy Christmas 🎄

[@PhillyDee215]

Cool video 😎

[@SchrodingersBox]

Thanks 😁

[@chrisaleman9674]

thank you

[@thecardoc100]

With a little practice with the newer "2 wire Hall Effect" sensors you will see the best approach isn't to use AC coupling, it is to use DC and rely on the full capabilities of the scope to show you the voltage changes. (Not all scopes are created equal and that can present a challenge that may force someone to test differently) Some of these sensors operate on as little as a 1/2 volt change and what this allows is to have a system that can detect any wheel speed down to 0RPM. With these sensors, you can make a full rotation of the hub just to make sure that all of the teeth (or magnets typically imbedded in the seal) are intact and then from there you only need to rock the hub from an "on" to "off" position. Here is why to test this way. Let's use a system where the reference voltage is 11v and it pulls the reference down to to 10.5 volt to make the signal when the wheel or magnet is near the sensor turning it on. By manually turning the wheel to the "ON" and stopping which is the 10.5v, the wiring harness and connectors can now be manipulated to see if the circuit can be disturbed. If there is an issue the voltage won't stay at the 10.5 and could go up to the reference, or go to 0v. Just wait till you get to play with some of the newest designs, some of these can even determine which direction the wheel is rotating. BTW, the comment about resistance checks not being valid is correct because of the solid state electronics inside the sensors, which of course is why the best routine is to measure the voltage just like the module does..

[@ProperRepair]

Great video (as always)! But is it possible that the original sensor is good? Perhaps it just doesn't work with this car (different supply voltage) or with the original bearing (wrong distance from the reluctor)?

[@SchrodingersBox]

Unfortunately not because it did not produce a square wave with 12V applied and the reluctor spinning. It was the right sensor for that bearing, it just didn’t work. it’s possible there was an open in the wiring harness and not the sensor itself though.

[@peterclayton4385]

Great video, Matt. I was under the impression that because inductive type wheel sensors generate their own voltage that the wires connecting to them would not carry any ‘base voltage’ when probed as there would be no need for signal or power to the sensor if it generates both itself?

[@SchrodingersBox]

That’s not always the case. (great question by the way). Most inductive (variable reluctance) sensors do indeed have a bias voltage. It’s a DC voltage of usually 5V but can be up to 12V. The AC voltage generated by the wheel movement rides “on top” of the DC bias voltage. The purpose is strictly for diagnostics by the brake computer. If the computer detects a change in the bias voltage it can code specifically for a high or low reference voltage which helps you identify if you are looking for an open or short on the circuit for that sensor.

[@peterclayton4385]

@@SchrodingersBox Thanks, that makes perfect sense!

[@hansvanrengs2642]

Hello Matt, With 2 wires you can'not say that its an inductive sensor these days. A lot of cars have 2 wire sensors these days en the signal rides on the "ground" or / and the voltage supply. Greetings Hans

[@georgebonney90]

Merry Christmas everyone 🎄

[@legallass9905]

💜💜💜

[@chads8720]

Merry Christmas

[@SchrodingersBox]

Same to you Chad, thanks for the long time supporting the channel my friend!!

[@chads8720]

No..thank you for putting excellent and informative videos up and taking pride in what you do...I'd hire you anyday. Its refreshing to see somebody taking pride in what they do.

[@TheRichardgomm]

Wouldn't measuring continuity/resistance on each corner be a valid test?

[@SchrodingersBox]

No- because it could give a false negative

[@roxanneabbott8424]

Will the regular Vantage work as graph? Not Vantage Pro.

[@SchrodingersBox]

it will but not nearly as well as the legend or pro. I believe the original vantage you are referring to is the MT2400. It’s really more of a graphing multimeter than a scope by modern standards. it’s enough to get away with at first but you’ll really want something with more speed plus I am sure it’s only single channel.

[@roxanneabbott8424]

@@SchrodingersBox okay thank you for answering, great job btw on your vids!

[@donaldisrael7147]

Would a resistance check be beneficial in this instance?

[@SchrodingersBox]

Oh absolutely!! I totally should be covered that. I am not sure what the spec would have been but I could have used the good sensor for comparison. Great idea!’

[@SchrodingersBox]

Yep Krystal is right. If the resistance test shows a bad reading the sensor is bad however if it shows a good reading you cannot be sure it’s actually good. This is why you seldom see me do resistance tests. As I have improved my skills I have realized they are very seldom applicable in definitive diagnoses so I rely more on voltage drop or functionality tests. I used to do resistance tests all the time as a beginner but now with more experience I realize that wasn’t the right way.

[@ciaranlowe5547]

Good video. It’s a MRE sensor. (Magnetic Reluctance Element)

[@SchrodingersBox]

Thanks, haven’t heard that term before!!

[@Kamel419]

allow me to attempt to nerd-splain what i think may be going on here :) it sounds like this internally uses an op-amp comparator circuit. what a comparator circuit does is essentially establishes a threshold of voltage for which to compare, then if the input feed is below that voltage it stays low. as soon as it hits the desired voltage though, it flips all the way high. this is useful for taking an analog input voltage and producing a square wave as you mention. if i were building a circuit* (*i am not an electrical engineer, so i'm certainly not any authority on the matter), the reason i would use a comparator is if i needed a higher sample rate than the analog circuit allowed for. for example, say i need to read something that happens 60 times per second, and my analog sample rate is 60 times per second, the circuit would be out of spec. on the other hand, it's not uncommon for a digital sample rate to be easily 4x as much (often, much more than 4x higher), increasing my sample rate to 240hz, which should allow me to measure 60 times per second. i will concede, a comparator circuit is typically used for finding the higher of two input sources (hence the name, it compares the two inputs), but the same principles are at work so there may be a better term for this use of an op-amp. still, based on your description it smells like an op-amp is in use internally in that sensor. i'd be interested if anyone could weigh in on the matter, very curious!

[@Everyday_Richard]

8 channel scope I bought off Amazon. Its a Hantek for less than 100 bucks. I did buy the low amp clamp, inductive pickup and a couple other things to connect to it though, so about 400 altogether. But this thing is coming in extremely handy. It will never be a Pico but its great to learn on. Here is a bunch of links to things I tracked down that work with this Hantek. I do not and am not affiliated with any of these products. Hope this is OK to post on here Matt? It took me a couple days to research out the test equipment that would work with this scope. I really like it so far. Just trying to help out people that might be interested but don't know what to look for. Merry Christmas everyone. 8 channel Hantek for Automotive www.amazon.com/dp/B01EZX2NXO/ref=cm_sw_r_cp_apa_fabc_FhM4FbEH8W8RR?_encoding=UTF8&psc=1 Amp clamp low www.amazon.com/dp/B06W2KFZLW/ref=cm_sw_r_cp_apa_fabc_PlM4FbF7R0MN1?_encoding=UTF8&psc=1 Amp clamp regular www.amazon.com/dp/B07NZSHK72/ref=cm_sw_r_cp_apa_fabc_nmM4FbSE7DSGH?_encoding=UTF8&psc=1 Coil on plug test www.amazon.com/dp/B07WGYRSM1/ref=cm_sw_r_cp_apa_fabc_VnM4FbJ7G9CMP?_encoding=UTF8&psc=1 Oscilloscope Mini grabber to BNC www.amazon.com/dp/B086PSR9RP/ref=cm_sw_r_cp_apa_fabc_IoM4Fb2R2ZF01?_encoding=UTF8&psc=1 Coil on plug ignition waveform probe www.amazon.com/dp/B01I87MUHM/ref=cm_sw_r_cp_apa_fabc_spM4Fb22C1AY6?_encoding=UTF8&psc=1 20:1 Attenuator made for Hantek www.amazon.com/dp/B01G8LS0I8/ref=cm_sw_r_cp_apa_fabc_fqM4Fb7SC3E34?_encoding=UTF8&psc=1 Hantek capacitive Pickup probe www.amazon.com/dp/B01B17VSH4/ref=cm_sw_r_cp_apa_fabc_UqM4FbSR2VF88?_encoding=UTF8&psc=1 BNC Female to Dual Banana Jack www.amazon.com/dp/B00VB62YT2/ref=cm_sw_r_cp_apa_fabc_DrM4Fb3AWS4HQ?_encoding=UTF8&psc=1 Mini current loop fuse buddy www.amazon.com/dp/B0017R5EHO/ref=cm_sw_r_cp_apa_fabc_xsM4FbFSBT9RW?_encoding=UTF8&psc=1 BNC male plug to dual female banana jack www.amazon.com/dp/B07TC1L8RP/ref=cm_sw_r_cp_apa_fabc_etM4Fb836SFKZ?_encoding=UTF8&psc=1 BNC to dual male banana adapter www.amazon.com/dp/B00VG5HWH2/ref=cm_sw_r_cp_apa_fabc_fuM4FbC7S0AAQ?_encoding=UTF8&psc=1 Regular fuse buddy Amp loop www.amazon.com/dp/B001A4FPC8/ref=cm_sw_r_cp_apa_fabc_ZuM4FbBMXY42W?_encoding=UTF8&psc=1 BNC male to dual banana female adapter www.amazon.com/dp/B07TC1L8RP/ref=cm_sw_r_cp_apa_fabc_AvM4Fb354E20K?_encoding=UTF8&psc=1 Pressure transducer 100psi (make other psi) www.amazon.com/dp/B0748BHLQL/ref=cm_sw_r_cp_apa_fabc_xwM4FbSVA2SHK?_encoding=UTF8&psc=1 Obd-2 breakout box www.amazon.com/dp/B089R86P2L/ref=cm_sw_r_cp_apa_fabc_zxM4FbVMHZSVW 2 pack LED bendable flashlight rechargeable www.amazon.com/dp/B08117XCCD/ref=cm_sw_r_cp_apa_fabc_EyM4FbAKA53Z2

[@Sam_Molina]

25:35 well said sir

[@alyameengomaa1048]

Hello sir I have Chrysler town and country 2003 and it was tuning ideal perfect but after I remove map sensor and clean it the car start but die after 1 second do you have any idea by the way I like you videos

[@SchrodingersBox]

No idea. what data do you have on the MAP output?

[@pl5882]

Did you try to run it without the sensor plugged in? It should run on a default strategy. If it does then you must have damaged the sensor during cleaning. I don’t recommend anything other than OEM on those if it needs replacement.

[@alyameengomaa1048]

Thank you sir for your replay that's right at be the map sensor is damaged as I use voltimeter their is 5. Volts wire and ground wire and 1.2 volt the last wire and when acceleration the signal wire still 1.2 volt no increase in volt

[@alyameengomaa1048]

@@pl5882 hello sire I changed the map sensor with a new one and the car works good every thing being normal but another problem happened the car stops suddenly and no crank no start and anti theft warning continuous light and oil warning no present

[@alyameengomaa1048]

Actually this problems happens 2 times before and the cars suddenly starts to run without I make any changes some body said that transponder in the key is the problem and others said that may be some wire harness present and actually I am confused

[@grenvillephillips6998]

It looks like a perfect justification for buying a scope. Ford might have avoided the problem by making the new parts number more distinctive.

[@SchrodingersBox]

Yeah I think it’s an aftermarket part manufacturer issue more than a Ford issue but whatever the case they need to get it straight!!!

[@Everyday_Richard]

8 channel scope I bought off Amazon. Its a Hantek for less than 100 bucks. I did buy the low amp clamp, inductive pickup and a couple other things to connect to it though, so about 400 altogether. But this thing is coming in extremely handy. It will never be a Pico but its great to learn on. Here is a bunch of links to things I tracked down that work with this Hantek. I do not and am not affiliated with any of these products. Hope this is OK to post on here Matt? It took me a couple days to research out the test equipment that would work with this scope. I really like it so far. Just trying to help out people that might be interested but don't know what to look for. Merry Christmas everyone. 8 channel Hantek for Automotive www.amazon.com/dp/B01EZX2NXO/ref=cm_sw_r_cp_apa_fabc_FhM4FbEH8W8RR?_encoding=UTF8&psc=1 Amp clamp low www.amazon.com/dp/B06W2KFZLW/ref=cm_sw_r_cp_apa_fabc_PlM4FbF7R0MN1?_encoding=UTF8&psc=1 Amp clamp regular www.amazon.com/dp/B07NZSHK72/ref=cm_sw_r_cp_apa_fabc_nmM4FbSE7DSGH?_encoding=UTF8&psc=1 Coil on plug test www.amazon.com/dp/B07WGYRSM1/ref=cm_sw_r_cp_apa_fabc_VnM4FbJ7G9CMP?_encoding=UTF8&psc=1 Oscilloscope Mini grabber to BNC www.amazon.com/dp/B086PSR9RP/ref=cm_sw_r_cp_apa_fabc_IoM4Fb2R2ZF01?_encoding=UTF8&psc=1 Coil on plug ignition waveform probe www.amazon.com/dp/B01I87MUHM/ref=cm_sw_r_cp_apa_fabc_spM4Fb22C1AY6?_encoding=UTF8&psc=1 20:1 Attenuator made for Hantek www.amazon.com/dp/B01G8LS0I8/ref=cm_sw_r_cp_apa_fabc_fqM4Fb7SC3E34?_encoding=UTF8&psc=1 Hantek capacitive Pickup probe www.amazon.com/dp/B01B17VSH4/ref=cm_sw_r_cp_apa_fabc_UqM4FbSR2VF88?_encoding=UTF8&psc=1 BNC Female to Dual Banana Jack www.amazon.com/dp/B00VB62YT2/ref=cm_sw_r_cp_apa_fabc_DrM4Fb3AWS4HQ?_encoding=UTF8&psc=1 Mini current loop fuse buddy www.amazon.com/dp/B0017R5EHO/ref=cm_sw_r_cp_apa_fabc_xsM4FbFSBT9RW?_encoding=UTF8&psc=1 BNC male plug to dual female banana jack www.amazon.com/dp/B07TC1L8RP/ref=cm_sw_r_cp_apa_fabc_etM4Fb836SFKZ?_encoding=UTF8&psc=1 BNC to dual male banana adapter www.amazon.com/dp/B00VG5HWH2/ref=cm_sw_r_cp_apa_fabc_fuM4FbC7S0AAQ?_encoding=UTF8&psc=1 Regular fuse buddy Amp loop www.amazon.com/dp/B001A4FPC8/ref=cm_sw_r_cp_apa_fabc_ZuM4FbBMXY42W?_encoding=UTF8&psc=1 BNC male to dual banana female adapter www.amazon.com/dp/B07TC1L8RP/ref=cm_sw_r_cp_apa_fabc_AvM4Fb354E20K?_encoding=UTF8&psc=1 Pressure transducer 100psi (make other psi) www.amazon.com/dp/B0748BHLQL/ref=cm_sw_r_cp_apa_fabc_xwM4FbSVA2SHK?_encoding=UTF8&psc=1 Obd-2 breakout box www.amazon.com/dp/B089R86P2L/ref=cm_sw_r_cp_apa_fabc_zxM4FbVMHZSVW 2 pack LED bendable flashlight rechargeable www.amazon.com/dp/B08117XCCD/ref=cm_sw_r_cp_apa_fabc_EyM4FbAKA53Z2

[@joecraigslist9467]

Damn. That's the scope I have.

[@SchrodingersBox]

Hahahaha. hey it works it’s just not really optimal for car stuff. But I have even got ignition waveforms on it among many other signals!!

[@enriquemartinez7990]

Thank you very much again man big fan here how do I go to get and you Pay Channel And how much I have to pay or how it works let me know thank you 👀🌿How can I contact you?

[@SchrodingersBox]

the paid channel (Schrodingers Box Quantum Mekanix) is at www.schrodingersboxqm.com. it is $3.49 per month. You can contact me at [e-mail].

[@judahschwarz3552]

PEBTAO - Problem exists between technician and oscilloscope - lol

[@denvernow7294]

Your thumbnail image looks like a sith lord or it could be Darth Maul's brother.

[@SchrodingersBox]

ROTFLMAO!!!! You are so right lol!!! I totally didn’t see it that way!!! That’s freakin hilarious man!!!!!

[@denvernow7294]

@@SchrodingersBox Completely post apocalyptic Darth vibes.

[@a.a.8572]

What software and what hardware do you use when doing scanning with you laptip. And is the combo you use more compatible with cars for the US market? Can I use it in Europe? And does it work better with some car brands then other brands? What does the software/hardware cost, And what is the cost for updates? Kind regards from Sweden

[@SchrodingersBox]

I use Auto Enginuity. Yes it works on european cars!