How to test a crank sensor with a voltmeter

The tests shown in this video apply to camshaft, crankshaft and vehicle speed sensors on ALL Chrysler models, in all production years. The vehicle being tested is a 1997 Jeep with a 4.0L engine.
Chrysler has changed very little in regards to their hall effect sensors throughout the years. Older systems used an 8-9v reference circuit (power supply), where the newer systems use 5v. And with all of them, the signal circuit is a 5v pull-down design.
Engine Performance Diagnostics chapter 21 pages 20-29
Tests shown
- how to check a crank sensor with a voltmeter
-what does an on/off digital signal look like on a voltmeter
- how to check the 5v reference and ground to the sensor
- how to perform a bypass test
- how to verify signal circuit integrity
Tools used
- digital multimeter
- jumper wire
- backprobing pins
- incandescent test light
- scan tool
Related videos
- 1997 Dodge Neon no start, crank sensor problems
• 1997 Dodge Neon no sta...
- How to test a crank sensor (Chrysler Dodge Jeep)
• How to test a crank se...
- How to test a cam sensor with a voltmeter (All Chrysler models)
• How to test a cam sens...
- 2003 Chrysler-Dodge 3 8L No Start (faulty crank sensor)
• Faulty cam sensor sett...
Playlist
(Chapter 21) Ignition inputs, cam and crank
• (Chapter 21) Ignition ...
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.scannerdanner.com/join-sc... 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.

[@Caradonia]

I just did a primary chain and balance shaft chain on a 2.2 GM Ecotec engine. When I first tried to start the car it wouldn't run too well. Got a P0340 code. I was thinking I made a mistake and missed a tooth on reassembly. Turns out I actually had a shorted cam sensor. I followed this exact process using my scope. 0.71v plugged in and 5v unplugged. No square wave during a crank. Powers and grounds were under good under load. I love this channel and the premium one. Great information as always.

[@404notfound.....]

You & south main auto are the top channels for automotive diagnostic services. 👍🥇

[@geraldmartin3625]

My friend has been mentioning problems with his sebring all of which are consistent with your chrysler, dodge, mitsubisbi 2.5 knocking, pinging and stalling vid from a few weeks ago. He has had 3 mechanics look at it and give up because there are no DTCs. The hour long video changed my directional mindset, I was going to look for a no com and go from there. I dont have a scope, just a simple handheld scanner with live data capabilities. This vid is exactly what I needed to confirm circuit integrity with a dvom. You Sir are very much appreciated, thank you for your time and effort!

[@joefernandez9522]

1111111¹q1

[@1drivingfast]

It's rare to find a mechanic that knows their sh#t. I'm working on my families now. Bravo sir.

[@dudemnky101]

shit how many families you got

[@CycloneCyd]

This video is awesome, man. It's so hard to find a Technician who REALLY knows his (her) onions like this that I wouldn't trust most to service a walking stick. I've done a video showing the DIYer how to get a good indication if the CKp is kaput and was thinking about doing something a little more comprehensive with a voltmeter, but instead I might just share this, it;s so good.

[@Seal00754]

I am a ex Royal Automobile Club Patrol (Auto Club) I'd just like to say that this video although to some very technical, would save you money in the long run. So many forums online talk a load of BS and at last I have seen someone without greed, show a way forward. The USA is a big place and dealerships can be only on the coast states. Well done. If you find a old Bosch Distributor with the hall effect, you can show the "window" clearly. But basically it's a gap within the "magnetic field that switches the transistor to ground". Nearly all circuits are ground switched as the 5 volts is used as a stable voltage opposed to the 12 volts. Which does vary with the starter engaged.

[@hustlerforgita7538]

Great video for someone who doesn't have a scope thank for your labor and explanation

[@bobdelaplage690]

Very informative brother! I check my no spark on my old volvo morrow, by doing exact these tests, its a 1992 and the sensor is on a hot spot on flywheel behind motor, may well be 30 years old and 250 ooomiles heatcycles...i do the diagnostics first, before trhrowing the other in, its rewarding to understand how they work / stop working, and the obvious tests to isolate the problem, great thx from Belgium Europe🇧🇪🍺

[@ShiversRSS]

I love all of your videos and I am having a crank sensor problem with my dad's jeep. This helped me out a bunch! I would like to suggest you add some tags to this video so that it's more easily searched in KZbin. Thanks again for the great video.

[@rikkimalloy9266]

Brother you are Bad Mr. I just love your style. In my opinion you are a automotive technician. Mr. Brother Man: I hard core salute You.in my younger years I’d love to be on your team. You spoke clear, you explained clear and I know confidence and ability in an individual soul stay blessed and keep on pushing. And thank you

[@battlehrfred]

Finally, someone explaining how the 3 pin crank sensor "in detail" ty so much for explanation on the diagnosis ,including the 5 volt rule and solenoid checks!!100-100

[@EdirtySicks]

Thanks for the offer! I am in SoCal though. BUT if you watch my last video, you can see me find the short after hours of being stranded on the side of the road last night. I needed light and couldnt see the angle at the harness i was testing, so my cell camera screen and light worked out perfectly. ;-) Thank you again for all the videos you post!

[@thealgerian4735]

great explanation. respect to what you re teaching here

[@nilorodel9278]

Thanks Paul,its a great help,you're a good instructor,you explained very well,,,

[@stargazer9172]

Love your channel. Mechanic from San Antonio , Texas

[@drm42]

Amazing video, super detailed. Thanks so much for sharing!

[@frankfrancisfrancis4919]

This video is very very clear and simple to understand

[@richgorsuch2667]

Thank you very much for making this video!!!

[@ScannerDanner]

@ExoVCDS I try my best to keep everyone engaged, sometimes it's just not possible. It is disheartening sometimes. Thanks for your comment though, it made me laugh. :)

[@bravobullz7475]

Came across scannerdanner because of a misfire problem I was having and between 2 “professional” shops and $800 later still had a misfire so I took matters into my own hands I was told that my coil packs were fine Well they were not New coils problem gone I can not thank the KZbin community and scannerdanner enough for making the content they do Now I just want to learn it all So my family friends and I will never get robbed by another mechanic 👨🏻‍🔧

[@yanfishtwig2356]

Indeed brother

[@alanchan1772]

great info for techs and dyi people.thanks for great video.

[@Luisvegabroker]

Your the man bro ! good instructor

[@collinjernigan1898]

Outstanding instructional video thank you sir

[@billnatan536]

You are a brilliant teacher.

[@ScannerDanner]

Thank you Bill!

[@faustogonzalez8397]

Awesome Paul , Love it!,

[@rickchapman3707]

Thanks Paul just bought your book really needed to brush up on this topic

[@ScannerDanner]

Rick Chapman thank you Rick!

[@ScannerDanner]

cool man, glad you fixed it

[@kolasamartin]

Thank you mate, this video helped me diagnosing starting issue with my Jeep Grand Cherokee :)

[@jamessnipervlog7383]

Very good instructor

[@payasito8132]

Nice job i really like your video's very helpful

[@ScannerDanner]

@ShiversRSS any particular tags you would recommend? i did put some in but could definitely use some suggestions

[@MaicSalazarDiagnostics]

Paul, I have notice that in the last part of this video when you are doing the bypass, every time you touch the sensor signal wire with the test light to ground the IAT(V) and the COOLANT(V) goes to CERO! It is exactly at 14:50 on the video. Why is that?

[@joshuagomez3600]

Great video, thank you!

[@hddm3]

man wish you were closer. i would take your classes for sure.

[@samwiggins5349]

thanks so much, i watch all your videos and you are teaching an old dog new tricks i have speed sensor problems on my isuzu trooper transfer case (TOD), i got to get under the truck, but i ain't buying a part i don't need

[@felplayvina]

TPS and MAP sensor 5 v supply are okay but today my van won't start it, checked fuses and relay good, I jumped pin 30 to 87 the starter worked. thank you for your replay Paul I really appreciate. I will replace the pcm, and see if that it fix..

[@ScannerDanner]

@DEFiANCE665 For sure, no problem at all. Thank you

[@import0408]

Another good video. Wish I would've watched this yesterday had one in my bay today with a bad cam on a Chrysler could have used this to help.

[@ScannerDanner]

@DEFiANCE665 V8 Jeep is all I remember, same test on all Chrysler Hall Effects though, other than the signature of the waveform

[@israelzunigamascorro9300]

excellent information Mr Paul. I have learned a lot of tips with your videos. Thank you for sharing your knowledge with us. God bless your family and you too. greetings fron Tamaulipas Mexico. sorry for my Englis writing.

[@ScannerDanner]

Your English is fine my friend. God bless you too

[@danpettis1675]

ScannerDanner hi Paul my supply voltage tested 4.92.i haven't tested with key on to see if my voltage dropped. Does it have to be exactly 5v .or is this close enough? Thanks in advance

[@ScannerDanner]

No problem at all at 4.92 v I've seen them as low as 4.7

[@danpettis1675]

ScannerDanner thank you so much sir

[@danpettis1675]

ScannerDanner is a cam sensor test the same?

[@kman-mi7su]

So I'm working on a 2000 Dodge Ram 1500 5.2 engine. I'm a DIYer and I just did the sensor ground test like yours. In your test before cranking the engine and the DVOM hooked up, it read .009 millivolts, mine read .018, double that. I that normal for the truck? Wiring is my weak point, but thanks to you and a few others I've learned a thing or two and want to learn more. I acquired this truck free after the owner got fed up and let it go after it was stolen and recovered. I had to replace the ignition after it was punched by the thieves. It has a crank no start issue, It also had a "no bus" issue so I replaced the computer and solved that. Trying to get this beater running so I can use it as a cheap household projects truck. Keep up the great work you are doing by educating us.

[@ScannerDanner]

.1 (100mv) or less is the standard for sensor and computer grounds. Your .018 = 18mv and is totally fine

[@kman-mi7su]

@@ScannerDanner Thanks, I only got to that point, then it started raining. Working in my driveway so I'm at the mercy of the weather. Rain today and tomorrow but thanks. Like I said keep up the good work I'm getting an education from your videos and I'm sure others are too.

[@antoniopereira4249]

THANKS FOR YOU GOOD EXPLANATION

[@rudy6458]

Great video for a DIY

[@felplayvina]

just a question Paul as I see .378v without the key in, on the crk signal wire I thinking to replace the pcm. also did the by pass test and hear nothing, any advise thank you.

[@donalddeanemcsemasterasecp1615]

Danner It is Funny How Those CPS Always Go Bad On A Jeep I Just Fixed One The 2 dealers Said No CPS And 2 Shops i Found It 98 L6 In The Side Of The Bell Housing 1 Bolt I Tested It.Was Deader Then A doornail Lol Changed It Runs like A Champ !! Good To See Some Of Your videos Are Still Here !!! I Send All My Do It Them Selfers To You !! I Owe You And Your Son a Big Dinner !! Always Following You,Best

[@nilorodel9278]

I followed your instructions and i found out my computer does not communicate,i open my computer and i check it and found you're right,the computer is the culprit,and then i search you tube about PCM why they fail,one reason (of so many i guess)is the capacitor,so i tried,i changed the three capacitor inside,now my jeep runs well,i hope it helps.

[@kennethdeneau7064]

this video provided the diagnostic procedure I needed. Saved much time & effort. Thanks.

[@ScannerDanner]

Thanks for watching!

[@danpettis1675]

ScannerDanner hi Paul followed your test to the letter. Everything looked great. Until I got to the sensor ground test .engine running kept flucuating between 14 and 26 millivolts. When I first started. (ASD removed) for a split second it spiked to 93 then would go down to 14... I didn't see anywhere near the readings you had on that chrysler.. bad ground maybe? Car does start and run .but keep getting the p0340 cam code. And has a stumble .And bucks and hesitation.. I've tried just about everything. It's a 06 jeep liberty thank you

[@nickoglock]

Another good video. I used this bypass test today on a 97 Jeep Wrangler 4.0 I ended up having a bad cam sensor which it was in the distributor The good part was the one I got from the part store was bad as well LOL It would've really thrown a normal parts changer around the bend I'm sure But since I had done the bypass test I knew that I had a bad sensor

[@elboregojhb]

Pick-up

[@ScannerDanner]

What is the feed wire voltage? Do you have a steady 9 volts? If so check either the TPS or the MAP and let me know if one of the wires is reading 5v there.

[@hensennguyen]

Ur great master. I will be study a lot :)

[@ScannerDanner]

You can use a test light, most pull-up hall effects are 12v anyway. Even if it was 5v you can still use a test light with no harm.

[@keithnoneya]

Did this on my 2003 Dakota and got not ASD Relay activation. It had the 5vdc like you did, both the feed and the PCM return or signal line. All the wires ohm out and I tried the ground pulsing on the PCM feed line and the ASD still didn't activate. The ASD ines all check good to the PCM and the Fuse panel, fuse good tool. I also have a NO BUS on the Instrument panel, 920 and 921 codes pop as well. My only conclusion at this point is the PCM must be bad. I reconnected the CKP and ran an oscope on the CKP to PCM feed line, and no pulses came out of the connector, so I probably have a dual problem, PCM and CKP. Thanks for sharing, I enjoyed the instruction. Best Wishes & Blessings. Keith Noneya

[@fortunerecords8154]

Thanks for this. I had similar issue but on probing the reference voltage with sensor pulled out, 5v appeared on both signal and supply. The ground was fine. What could be wrong?

[@xevietthoviet9178]

I watch the video of the teacher, looking forward to the last day as a student I come from Vietnam

[@mobmob5944]

@Jamison Grotzinger i just hacked your ip adress server and the first reply to your comment and they are both from the same adress no im not gonna look thru your pics lol 🙄🤫

[@acuvetis6699]

Great stuff.

[@seanfancy9949]

Thank you for this video. one question are you saying that the Pcm Crankshaft position sensor line has an output of 5 volts from the Pcm?

[@randyanderson6110]

Would that test work with the Jeep 87-90 renix 4.0 as well. The renix sensors are 5 volts and hall effect.

[@nickayivor8432]

SUBSTANTIAL Sir ScannerDanner Thank you👍 Sir ScannerDanner From Nick Ayivor from London England UK 🇬🇧

[@raymiefarr1]

Thank you!

[@felplayvina]

Hi Paul, a bad crank sensor only will do no signal right, but with the sensor plug in the 5V should be there or not? is the wire is good with the sensor unplug the 5V should bee there..

[@pigeonsil240sx]

hey paul would it be more accurate if i put a rachet on crank pully and slow turn crank by hand since meter cant keep up with crank? then just look for the 0-5v change? (depending on if its a 5v signal that is)

[@ScannerDanner]

Is that with the sensor unplugged?

[@Happy357mag]

Thank you.

[@johnneneece4994]

big fan of all ur vids. been invaluable for a shade tree like me. something I haven't been able to find are some wiring diagrams, please point me in the right direction

[@greygoosemafia]

I have the 99 ram. tons of intake issues. I was thinking about welding the hughes plenum fix plate to the intake. would that be dangerous?

[@ScannerDanner]

Before you do that make sure the signal wire to the CKP sensor is not shorted to ground.

[@geoffrwelsh]

I wish your videos had been around years ago when I was struggling to teach myself all this stuff. I watch now just to stay fresh. Thanks for doing this. ps, the cheapo Ideal meter made me laugh; I can't afford a Pico scope, but I do have a Fluke and an OTC Solaris

[@CoolasIce2]

Good info.

[@ScannerDanner]

I believe the PCM is behind the passenger kick panel right? If so take a look at the connectors and make sure they are not corroded. I had a 96 with a windshield leak right onto the computer and caused to crazy stuff. BTW we are in Pittsburgh PA if your close we would love to help.

[@2001BornAgain]

How do you test brand new one before installing it? I wish you had one with a bad ckp and you tested the new one before putting it back in. My new ckp doesn't have any magnetism, but the old one does. So I am wondering if it is even any good. Any ideas?

[@thedobermangang3503]

good video smart man

[@pablogaibor9887]

Hello greetings from Ecuador, congratulations for the videos are very good! I have a question i followed the steps you describe here, I have a jeep xj 1998 it have misfire and before of that Check engine light P1391 i check connectors and found one pin dirty clean it up check engine light gone, but again starts misfire, i measuring the power supply voltage of the CPS sensor with the switch open I have 5v, but with the engine running it drops to 2.5v is this normal? Faulty wiring? Faulty sensor?, i cant check with a scope the wave sensor.

[@downcross1010]

thank you very much.

[@rikkimalloy9266]

Also is it possible for you to show and explain the wiring diagram for a 2006 Dodge charger 2.7

[@movingupautodiagnostics8645]

Hi Paul, since this is a 5v pull down hall effect sensor, it's easy to ground it with no danger by doing so but, is there a 5v pull up design? If so, I'm guessing that I can't use the test light from B+ since its 12v. Can I jump the 5v power feed to the signal wire to do this bypass testing??

[@ScannerDanner]

No danger in grounding a 5v pull-down circuit, even with a jumper wire. I've never seen a 5v pull-up but if there was one, you could still use your test light and tap into the 5v ref circuit from another sensor.

[@movingupautodiagnostics8645]

ScannerDanner got it, thanks.

[@danpettis1675]

ScannerDanner hi Paul. I measured my 5v reference at 4.92v (No crank ,key on) is this close enough. I was told that the reference voltage is never perfect. And I should be fine.i basically wanted a second opinion thank you in advance

[@kasman72]

if you have a 12v ref voltage and it drops to around 11.2 during crank with a no start condition should i look to the starter?

[@lwigaleabel6211]

Gud teacher thanks

[@mrexecutive1]

Is it possible to use the Hertz setting on the multimeter for cam/crank signal?

[@pabloarevalodelaguila8767]

Very Good

[@ScannerDanner]

That is a good question David and I didn't notice that until I uploaded the video. I am not sure I can answer it. What I can say though is some inputs are not updated on scan data until there is an RPM signal. With me providing a false RPM input, this could be a factor. What I don't know is why the numbers would drop to zero.

[@Ukiyoez]

I have a 1999 suburban C1500 5.7L. Crank Position connector disconnected. Is ground supposed to disconnect when ignition is on? Ground is there when ignition is off.

[@OmniBear]

Why was the IAT and coolant temp voltage dropping to 0v when you were doing the bypass test at the end of the video?

[@FahimMotoGP]

reading looks good on meter but my sensor still causes no start condition. I already replaced the sensor, can it be a faulty new sensor?

[@Z_732]

I'm a little lost on mine.. i did the remote wire test. Key on engine off. Positive to remote wire, negative to the battery -.. it showed 5 volts. I bumped the started a couple times to double check. Same result. What am I missing here? If you don't mind. (Yes the power side also showed 5 volts)

[@stuckinmygarage6220]

Gold 🥇. New sub - new student.

[@ScannerDanner]

Welcome! Looking forward to answering your questions along the way

[@stuckinmygarage6220]

@@ScannerDanner Thank you. I'll start watching. Happy New Year!

[@ScannerDanner]

@stuckinmygarage6220 definitely the Topdon Phoenix Lite 2 it's around $800? They make one that's around 500 but I don't know enough about it yet.

[@felplayvina]

yes it is unplugged, I thinking to cut the wire from the pcm just to see if the voltage disappear, because it connect to tcm also.

[@mohanedmohamedahmed9603]

if we could manually turn the fly wheel like when we do for leak down test . can we catch this at full scale ??

[@josephlbrociousjr3951]

The most important part I needed to see,,,,,,,, Kinda difficult to show you that.

[@ScannerDanner]

Anything I can help clarify?

[@JRLSB]

Im confused im looking at a wire diagram for this and the red wire says 5v supply and the black /white says signal but u keep says the red wire is signal so is the wiring diagram wrong? when u diconect the plugg from the sensor then it reads 5v constantly so when u ground it with jumper ur acting like sensor and comolete the circuit.

[@prinsafro2148]

thanks lots for your work. how I can now wich car sictem? ? you have some help? ?

[@ScannerDanner]

your welcome!

[@athiam152]

How about if a crankshaft sensor reads 8V on the CKP sensor and Car battery is at 11.9V ? What should I do? Car is 2006 Honda Accord Euro CL9

[@ScannerDanner]

on the older ones they used an 8-9v power feed to the hall effects. either way I don't like 7v. double check that again and make sure your meter has a good ground and also give me the exact number. (example 7.99V is a lot better than 7.23) you should be closer to 9 v on your system in the feed circuit only. The signal is still a 5 v pull down design (sensor unplugged you should read 5)

[@BlueStar712]

Thank You for this info. Very good .

[@sivucit]

hi, this video is for pull down, ihowver n PULL UP sensor , can i use test light for signal to bypass the sensor to bring it to 12v but the problem is test light is 12v, how can i limit to 5 volt, ?. or even though test light is 12v, ECM will consider max as 5volt. please advise.

[@ghazanfarsmith6608]

hi great video shouldnt that 5 volt turn to zero signal wire connected to ground.

[@brentbrown9728]

Would a sensor going bad cause power to be cut to a fuel pump? trying to trouble shoot a Dodge Stratus that won't start.

[@pupuffpass]

Awesome explanation love the video. I have a question about an issue I'm having. Testing both power and signal wires without the sensors plugged in should read 5 v right. Well when I do the bypass test the cam reacts like it should but the crank reacts to both signal and power wires tripping the relays on both wires but what's weird is that aren't they connected together with one power feed feeding both sensors. Or actually the speed sensor as well right? So if the wires were touching then wouldn't it have the same affect on the other sensor wire harness or does the signals relay back to the ECU separately

[@ScannerDanner]

So with your bypass test, you are jumping those circuits to ground? You shouldn't do that to the reference circuit.

[@felplayvina]

Hi Paul 98 vanager 3.0 still no spark, I been reading your book really good. I just follow your instruction all power to pcm and 9 and 5 V supply and ground are okay, this what I found cran sensor signal with key off .378V key on 68.0 MV speed sensor key off 00.7 MV key on 07.4 MV I just can't find the speed sensor location, little help please.

[@antonlammers1454]

In a pulldown setup: If you read 12volt on the signal circuit when it should be 5v(unplugged from sensor) could it be a short on signal wire to power or bad/open ground?

[@stuckinmygarage6220]

Are you sure it's a 5V pulldown? My GM 3.4 is feeder B+, with pulldown.

[@waqasazmat81]

Hi Paul, quick question. Since its a pull down design voltage appears as soon as sensor is unplugged. Question is if the signal wire was shorted to ground (external short) we would not see this 5v appearing with sensor unplugged. How do we then find out if it is a pull down or pull up design. I suppose we can check another hall effect sensor on the same vehicle or I guess depends on what the fault is stating regarding sensor signal.

[@ScannerDanner]

Great question! This information is not readily available, so if you didn't know, I teach to use a test light as your bypass tool, and then in your example you would connect it to battery positive and try to trigger the circuit, but the light would light up indicating a short to ground. On a pull-up design (which is what you would think with 0v unplugged), a test light to battery positive should NOT light the light. Hope that makes sense. If you're interested, this would be chapter 2 and chapter 21 material in my classes at www.scannerdanner.com Thank you!