How to Test Crankshaft and Camshaft Position Sensors

How to Test Crankshaft and Camshaft Position Sensors


Hey there do it yourselfer’s today I am going
to show you how you can test and diagnose problems with your camshaft or crankshaft
position sensor. Now its crucial that you know how to properly test these sensors because
as some of you may know a bad crankshaft position sensor or depending on your cars make and
model a bad camshaft position sensor could cause a crank but no start condition. And
thats because if you have a bad crankshaft position sensor you are not going to be able
to get spark at your spark plugs and therefore your engine is not gona run. But if you have
stumbled upon this video because you have a no crank no start condition I suggest you
watch this video which I made recently I’ll put a link to it right here on this side of
the screen I’ll also put a link to it in the description box, in that video I go in pretty
high detail how to diagnose a no crank no start condition. And as far as where these
sensors are located, your crankshaft position sensor is gona be usually on the bottom of
your engine right by your crankshaft gear behind your harmonic balancer usually, but
there are few applications out there where the crankshaft position sensor is located
on the back of the engine on the bell housing. And your camshaft position sensors are usually
gona be located towards the top of the engine behind your camshaft gears. Now there are
more than a few different types of camshaft or crankshaft position sensors but for this
video we are just going to concentrate on the two most common ones. And the first one
is going to be this magnetic type sensor, now these sensors will almost always have
only two wires going to them and these sensors produce their own voltage. And the way these
sensors produce their own voltage is that when your crankshaft or camshaft gear turns
right in front of your sensors the teeth that are on your gear are going to stimulate the
magnetic field at the end of these sensors and than your sensor is going to produce and
AC voltage thats than send to your electronic control module through this wiring harness
connector. Now I am going to do this testing procedures right here on this bench but you
dont have to remove your sensor you can just do this on the car. First thing first you
want to closely take a look at the plastic housing of your sensor if you see any major
cracks or signs of damage or if its bent out of shape than that could potentially mean
you have a bad sensor. After that we are going to do a resistance test, so get your multimeter
put it on the ohms settings and this subaru crankshaft position sensor is supposed to
have about 2000 to 2500 ohms of resistance so I am going to choose 20,000 ohms on the
scale of this multimeter, and than we will take our measurement. And as you can see we
got 2.01 thousand ohms of resistance or in other words 2010 ohms. Also its very important
to check the condition of the connector for your sensor as well, sometimes oil and dirt
and mud gets on this sensor and causes all sorts of problems, But if it looks clean or
if you clean it than its a good idea to check and make sure that you have ground at this
sensor. So what you want to do next is to ground your black test lead and it doesn’t
have to be to your batter you can just ground it to your engine or chassis, than we go over
to our multimeter and we are going to choose this setting for continuity which we will
also hear a beep if we do have continuity, and with our other test lead we are going
to test our ground wire and if we hear a beep that means we got ground and we are good there.
The last and most important of all is to test whether this sensor can put out voltage. Again
these sensors put out AC voltage so you want to get your multimeter and put it on AC volts
and we are gona go with 2 volts and since most these sensors only put out about .2 to
almost 2 volts. Now a scope would be a much better tool to use inorder to measure the
voltage thats coming out of these sensors but I am going to assume since most people
don’t have one of those we are just going to be using this multimeter and if you are
going to be doing this on the car as your as the engine cranks you know you may not
get you may not see the voltage go up and down as its supposed to because your multimeter
may not be able to keep up but you may just see one solid reading lets say like .15 volts
being put out by this sensor but that usually means that you got a good sensor or in other
words a sensor that can put out voltage. And if you are bench testing this, this is basically
what you are going to see, as you move this gear past this sensor, you are going to see
the sensor produce a very tiny amount of AC voltage for some reason this works better.
Alright next up these 3 wire sensors, now unlike the previous sensor these sensors don’t
produce their own voltage and they require 12 volts to operate so basically they receive
12 DC volts from your ECU and than based on the position of the teeth on your gear they
make adjustments to that voltage and than they send that voltage as a form of a you
know a signal voltage back to your ECU they also have a grounding wire as well. So with
the Key ON or in the Cranking position you always have a constant supply of 12 volts
to these sensors you always have a constant ground. And if you want to test these sensors
you want to make sure you ground your black test lead and than you want to put the setting
on your multimeter to DC volts and our constant sometimes is 12 volts other times is 5 volts
just depends on your cars make and model but all of those are going to be less than 20
volts so we are going to go with 20 volts on this setting. And than you want to remove
the wiring harness for your connector and than test each pin and the one that gives
your voltage you know thats your constant wire, so here in our case is going to be this
third and last one which is giving us 12.2 volts so we are going to write this one down
this red one as our constant wire. So next we are going to find our ground wire from
the two remaining wires so while our black test lead is still grounded we put our settings
on our multimeter back to ohms and than we test the two remaining pins. And the one where
we got next to no resistance we put down as our ground wire and therefore right now not
only we have verified that we are getting voltage but also we have a constant ground
and the remaining wire has to be our signal wire. Now as far as how you can test these
basically you test these on the car you get your multimeter put your setting to 20 DC
Volts and than you’ll need to back probe your ground and signal wire and than connect these
to your test leads by alligator clips, and if you want to have an easy job of doing that
make sure you use some paper clips to back probe these. And than with the engine cranking
or running you’ll see the voltage thats coming out of your signal wire and again you are
not going to see it go up and down like its supposed to but you know it will verify that
your sensor is putting out voltage. And thats all there is to it folks now I am going to
put some other video’s where I use the multimeter to test other screen so you can just click
on them but if you found anything in this video useful please give it a thumbs up subscribe
if you want to see more like it and I’ll see you next time. Thanks for watching.

About the Author: Michael Flood

100 Comments

  1. If the crankshaft sensor is not installed all the way in cause a wrong seald ,the car don't start ?? Please help

  2. Mercedes E320 96..I pull off the conector from sensor and mesure all 3 conector contacts ( ig. key kontact right end position ..) I mesure 12 volts right and left side.. But strange is that i mesure 12 volts at the midle also..!? How come ?? I hear something (like a small el.motor running) when I stop cranking..? Wierd..

  3. Thanks friend for all your videos and help. I have a 2000olds intrigue. And i might have to replace crank sensor . But i also need to do a relearn . What kind of scan tool can i use that can program relearns? Any suggestions as far as brand or type ? Thanks

  4. I have a question should the signal wire show any voltage when not plugged into the sensor mine has 5 volts and 2.81 volts when plugged into the sensor

  5. Thank you for these tutorials! But I have a question, how do you test a camshaft position sensor that has three terminals? My Megane 2005 has three pins inside the connector. It's otherwise the same type as the first one you test on this video.

  6. So at the end of the video, you are saying if there is a change in slight voltage while cranking then the sensor is working? I have a 5v on signal wire with key on car off.

  7. Replaced timing belt on a 2.3Lin 1994 ford ranger got back together and crank spins but cam shaft doesn’t. Can anyone help me with this

  8. So if car or truck hesitates and bucks and lack power can it be a bad crank position sensor?? i have tried everything i can think of..replaced MAF sensor, cap ,rotor ,cleaned Map sensor…replaced timing chain.. Has 60 psi fuel pressure constant with key on …its a 2001 chevy 4.3 blazer… has no codes it did have a PO101 but its gone now and no codes come up even added seafoam and 10 gallons fresh gas to tank thinking gas was old… Anyone ideas are appreciated… thanks

  9. If the roof comes on the garage he can get a job teaching mechs and sparks at the local uni , he concise and easy to follow!

  10. No start on my 89 240 volvo. Fuel pump and relay good, and ample fuel flow when fuel rail opened. Cars gets spark at plugs. I suspect its not firing the injectors Also on one of troubleshooting tests (engine cranking signal) it fails.Question; even if I get spark can a faulty crank position sensor prevent a signal to operate the fuel injectors or some other component to cause a no start problem? Thank you in advance.

  11. My Toyota corolla won't start back after driving for some minutes left for ten or so minutes when cool will start any idea y

  12. You are a life saver. I have a 06 Subaru inpreza 2.5 turbo and it was breaking my head for 3 weeks. Thank you. You have no clue

  13. Nice job explaining the differing voltages from the 2 wire sensor. This is what I needed to troubleshoot a problem with a new cam shaft sensor that appears to be faulty. I am at my wits end in getting this car figured out. As we know it is not always good to buy cheap parts which was the case on this car. I bought the cheapest cam position sensor sold on ebay so after a no voltage test as you outlined in this video I returned it and ordered the next more expensive one from a different manufacturer. All a person can do is get money back for the bad part. It does not cover the agony of going to the next hours trying to troubleshoot the next potential problem that might cause the car not to start. On a 97 MB E320 this could be a number of items which all relate to no injector pulse or a no start condition. THe question arises what sensor triggers spark and which one triggers injector pulse. Is it the crankshaft sensor or the camshaft sensor. Guess I will wait till the new sensor arrives to be sure. Next if this does not work I go to retest the crankshaft sensor which is also new and a bugger to get out. I have spark cause it runs if I put gas down the air inlet port to the engine. Have you run across a situation like this one? Thanks again for sharing your expertise. J

  14. I changed the sensor after diagnosing bad camshaft position sensor and the check engine light turn on, the light went off on clearing it but later came back, I also notice that the car can start even when I unplug the sensor, what could be wrong?

  15. Oh, wow, at first I thought this was the typical "mechanic in his garage"-type video which, while quite useful, are usual really low quality and mostly talking (and a ton of noise in the background) and little showing, but this is really high grade with a bunch of stuff prepared beforehand to teach us better. Good job!!

  16. I don't understand why does it use AC electricity on the test?
    Supposedly sensors and many components work work with DC Electricity (converted from AC to DC)

  17. I have a 2003 Kia Sorento when it's some Park and I accelerate and I keep it on 2000 RPM for a while then I release the gas and the engine shuts off

  18. 2:24 and 5:33 surely this test for ground is bad unless you disconnect ECU FIRST and know what pin it is and check there ? doing the way he says here by sending voltage down an earth wire into ECU is BAD ??? a continuity test uses voltage to test dont they or am i getting this wrong ??

  19. So i have no spark on the cylinders. I changed my crank shaft sensor but still nothing. Is it my camshaft sensor then? All my fuses, and relays are good.

  20. You can tell when someone truly understands a subject because he can explain it in layman terms. Well done and thanks for the channel.

  21. Great video man. Way to explain the volt meter function. What if your engine is running fine then shuts off. After about 5 minutes it fires back up with no issues. But will repeat. I've already replaced the ignition module to no effect. This is a 2.5L Ford 4 cylinder

  22. how do you know what ohms you're supposed to put it on?. like say i have a 2014 kia soul 1.6L. What would be the ohms i put it on?..

  23. Great info. But when these sensors warm up, can be a fail.
    Do you recommend a mileage replace for these parts, b/c lets face it, nothing lasts forever

  24. For the continuity test for the two wire sensor, you have the black wire connected to one end of the green wire but do not show where the other end of the green wire attaches. Similarly, the red wire of the connector just appears to lay behind the volt meter. It gets confusing when you cannot see where all the wires are supposed to attach.

  25. I have a 2012 honda insight HYBRID 1.3 . Just replaced the engine and now it cranks but does not start. I have no spark and no injector pulse. There is a wire harness that connects to the cam sensor tonthe crank. There is no other wires going to it. How does it get power? How do i test. The sensor has three terminals

  26. Any test like that you should use a scope as you said but if not available than use a Analog VOM instead and you will see better sweep movement from the output.

  27. Well, I have an Acura MDX and the cranksensor has 6 wires not easy to know whish wires to test unless having the book, it has gas, has spark, has fuel pressure check all grounds, timing is correct, I had it running but as it was smoking changed the steam valve seals now it just won't start, one more test I still have to do whish is the fuel injectors but by now it only cranks

  28. Helpful video, but what if you have both codes, which happened to my sons 2003 Mitsubishi evo. I have heard that a bad alternator diode, or even a weak battery could be the cause?

  29. Lol….watch my video on how to test a sensor in less then a minute without all that…i just discovered.if your sensor sticks to metal its good…if it dont its no good….now wasnt that more simple????? Then all this bs. Thank you.

  30. Hi, I have a 1996 lexus ls400 crank but not start, does my car have crankshaft sensor and camshaft sensor or just one?

  31. Hello! Thanks for your great vids! I have an Audi 1,8T -99. My crankshaft sensor is an 3-wire type magnetic. Can i fault measure with ohm on that and how should i do then? What shall it show?
    If i have left, middle and right. Shall i measure on left and right and get an value for ohm then? There shall not be an O.L?

    I have just got the sensor loose from the crankshaft and from the connector contact, and it would be nice if i can measure on spot without take the cable install. away from engine.

  32. I have that problem crank but won't start and I can't find my crankshaft or camshaft or the coolant sensor on 2010 Hyundai Tucson there are no videos or diagrams any ideas?

  33. This sensors some times quit wen hot and wen cold they work fine until they get hot again and leave you stranded again it happened to me on my 97  Grand Am , is was a 17 bucks at AutoZone   just change it , my 2005 Chrysler 300 has 250K miles I changed it for no reason and the old one I put it in the trunk for emergency  cuz they are so cheap  ,

  34. Love your videos man !!! Being a mechanic myself the only thing I seen that could be not right…. When you were showing continuity,, I'd you have a 18 gauge wire with say 41 strands of wire in it, if 40 of those wires are broke or curroded your multimeter will show continuity. But will not carry enough current to operate the sensor. Need to show testing the wire with a couple Amp test light, depending on the circuit. Should make a video about load testing wires 👌

  35. Hello, I have two wires to crankshaft sensors, when I test them to ground no continuity, but when test them to + on car battery have continuity? What that means? Car cranks but wont start, sensor passed all tests and it is good. Thank you

  36. Being as I am English, I could not understand much of what this guy was talking about, he spoke far too quickly for me to take it in.

  37. Hello sir
    My problem is #4-5-6 cilynders are working on my honda pilot.
    At soon i disable those that are working by desconecting the wires
    From the coils.
    Then i started up again and #1-2-3
    Start working.
    But at soon i reconet #4-5-6.
    #1-2-3 dont works and there is compresion and spark.
    I know is the computer that disable them.
    But i dont know why???
    Can you or someone help me on this please..
    Daniel:)

  38. Hello subscribed and thank you for all your useful info. I had a quick question, diagnostic tool keeps saying crankshaft position sensor needs to be changed, replaced it and still getting same error. I am getting crank and start but am not able to go above 3000rpm even if i floor it. Any solutions, thank you

  39. Good video but I too am think that voltage from the computer to the crank shaft position sensor is 5 volts not 12 volts.

  40. hi sir 3wire crank sensor so gt ground n pcm put on 20v if volt go up that show crank sensor is good??? hagd1 sir

Leave a Reply

Your email address will not be published. Required fields are marked *