2009 Chevy Silverado Troubleshooting an Intermittent Crank Sensor Fault

How do we bill for something like this? This is a condensed version of an upcoming SD Premium video where I discuss this in more detail to help shop owners who handle these types of problems.
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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.

[@farmermiyagi1338]

I just finished with a Malibu that had a P0335. It came from another shop. They replaced the sensor (twice) with aftermarket, and the connector, and the PCM. After checking it out more thoroughly, and contacting the other shop, I found out they used aftermarket sensors. I waited a week to get one from GM. Problem solved. Same scenario, tach dropped out, long crank time. The aftermarket sensors NEVER lost the signal or glitched out on the scope, but there was something about it that the PCM did not like. The signal looked perfect when compared to the sample. I will never install aftermarket sensors, and now neither will the other shop.

[@D2O2]

The problem with looking at scope waveforms is not knowing what is acceptable and what is not.

[@farmermiyagi1338]

@@D2O2 I had a sample waveform that matched perfectly. The only thing I noticed is what appeared to be interference at the top of the waveform. Otherwise it looked perfect. Even when the tach quit, the waveform never changed.

[@D2O2]

@@farmermiyagi1338 So, the interference at the top of the waveform made it different than the sample. Do you know where your sample waveform was within acceptable limits? If it was on the edge, any slight deviation of the measured waveform could exceed limits. Visual comparison is good, but measured comparison is better and you need to know the limits of acceptance. Obviously, if the PCM didn't like it, it wasn't acceptable in a way that wasn't visible to you.

[@farmermiyagi1338]

@@D2O2 Thanks for that obvious statement. The sample was in the scope information archive. I did not scope it after the new sensor, because it worked. Vehicle has been returned to the customer with no issues since. ;)

[@verajavi12]

I thought I was the only one with an aftermarket sensor that displayed what I thought was a good scope waveform.

[@calholli]

I don't consider this being a "parts changer" -- You did due diligence and looked at the wiring and really narrowed it down as well as you could until the sensor change was a last resort. It could have been just a loose connection at the plug itself- but you would still have to pull the starter to deal with that-- so you might as well change to a new sensor while you're in there. Given the mileage on the truck, I like the approach.

[@johnjohannemann1220]

I say this respectfully, welcome to reality, my friend. As always great job and expressing yourself, showing the process and keeping it real. It’s just one of the many reasons I love watching your videos. Hope all is well.

[@DillonTurner395]

25:29 as eric o would say "CHEVY THUNDER!" 😂

[@bobbender2788]

Just fixed one today in my shop po335 customer supplied crank sensor, replaced still p0335 long crank, traced wires found one broken near the power steering pump where wire harness goes along front of oil pan, easy fix but time consuming to locate broken wire. also replaced two cross members in rusted bed . " Like a rock"

[@ianhart356]

Beautiful neighbourhood... enjoyed the drive and the diagnosis. Thank you!

[@mikew1332]

Excellent advice setting up the scope and watching while you begin poking around or moving anything.

[@isalmankhan1]

Really appreciated, Thanks for sharing SD😍 Stay Blessed Danner Family❤️

[@arthuraucar3696]

Very informative video.! My strategy is doing a visual and wiring contact points. If I can't prove a problem in the wiring harness, most of the time I feel confident replacing the sensor. This works for me most of the time, however I do understand there are times when is not the sensor.

[@dannypalmer7701]

Even a brand new sensor can have a intermitting problem too.Right out of the box!😮

[@calholli]

I always keep old radiator hose.. and on rub points like that: I'll take about a 4 or 6 inch piece of hose and cut it to shape; maybe split it into two half round pieces.. and just tape that around the rub point as a shield (after any repairs I did there). This just ensures that you won't ever have to worry about it again. I do this kind of thing a lot on big projects where you have to tear half the engine apart, such as a timing belt job, etc.. You'll see little metal heat shields and rubber hose shields all over my cars. lol.. I don't care, it works great.

[@alexisjohnson9608]

These videos really help great knowledge to have because you never know when you run into that exact problem and you need it.. And Happy Thanksgivin 🦃 brotha

[@Pablo_Automotive]

Thanks Paul for another great video

[@High_Tech_Mountain]

Out of all of this I can’t believe Beau is of driving age! Hahaha God bless brother! Still have half of the video left to watch! Looking forward to it!

[@High_Tech_Mountain]

If nothing else it’s a testament that you can pierce wires as long as you seal them. Good for years to come!

[@ScannerDanner]

Crazy right! Thanks for following along for such a long time!

[@douglash3129]

Happy Thanksgiving to you and your family Paul!!

[@ThunderbirdRocket]

Very helpful ! That certainly makes sense !

[@James-fs4rn]

👍 thanks for sharing! Happy Thanksgiving to y'all!

[@torsson2]

On a Saab 9000 you can diagnose a crankshaft position sensor with a puddle of water. If the car dies when you drive trough the puddle while steering right you need a new sensor :D.

[@apostlejohnzulu]

Oh yeah thanks very much for your response, what I meant was what are the safety precaution measures to take to avoid cars catching fire when working on ignition and fuel Manuel testing or when dealing with electrical check ups.

[@ScannerDanner]

That's a lot to put into text! In short, you should never test for spark while you have a fuel line open 😉 And don't use brake or carb cleaner to find vacuum leaks

[@FixIt1975]

I had a similar issue with my old, 2007 Dakota. Mine was often a warmed up, no start. It NEVER set codes. At all. I don't typically drive around with the scanner in the truck, either. Mine was an air gap issue. The crank sensor was just over 20 bucks, so I took the big, fat guess approach. Sensor came out in pieces. Twist and wiggle didn't work, it was rust jacked BAD. I got most of it out with a self-tapping screw and a slide hammer. Drove it 2 more years without issue and sold it without problems, just a bunch of body rust.

[@1MiketheMechanic]

Good video Paul. Sometimes it's more economical to take that chance but the customer has to fully understand the options and gambling odds. I disagree with the aftermarket sensor. It can introduce the didn't fix it but should have fixed it scenario we all love so much.

[@InsideOfMyOwnMind]

Benefit otd time, Could he even get the OEM sensor given the current cluster🖕with the parts supply chain?

[@ScannerDanner]

I took a chance with aftermarket for sure, but it worked out fine on this one.

[@jesusayalaalvarado6561]

Buen video de replazo de sensor y reparación de corto circuito sd

[@michaelwitmer7536]

As far as charging goes, each problem is a different diag. point blank. You don't get to let your car develop problem a,b,c,and d, then pay for a diag that covers all of them. Allowing your car to go down the toilet, like that, will cost more than repairing them as they arise. But you guys know that. Working for a tire store at one point in my career. They would sell the all inclusive diag for an hour. And that's why I quit working their. Only people that don't do the work would charge wrong. Thanks for all you have done for the industry.

[@ScannerDanner]

Exactly!

[@advancedleveldiagnostics]

Great video, Thanks for sharing! Do you think a crank relearn would have done anything?

[@ScannerDanner]

No sir. This was a bad sensor

[@aymenmohamed1134]

Awesome

[@Santiago_Ordonez_]

Exellent. 👌

[@juanolivera9361]

What a parts changer!

[@darinjohnson7280]

Have seen some issues with these 07 to 14 trucks with the engine harness rubbing through where the harness runs over the LH valve cover between the 2 front coils. There is a stud for the coil bracket that can pierce the harness. The stud does not need to be there, I always replace it with a bolt to prevent future problems. Fought one that shorted the 5 Volt wire on that stud, first time took a while to find, but seen it several times since..

[@ScannerDanner]

Thanks! And for sure! I even have a video on that condition!

[@mechanikartysta]

Great video. Temperature and ohm meter test could resolve all your doubts. CPK like to fail when its too hot or too cold even sometimes somewhere in between. 😊

[@ScannerDanner]

I've never, not once, used the ohmmeter on a hall effect sensor. The problem with resistance measurements on these is it is a static measurement with no switching of the internal transistor taking place. Also, a good resistance reading can still be a bad sensor. Labscope and signal voltage monitoring is far superior and if you don't see it there, you won't ever see it. Thanks!

[@michaelwitmer7536]

In my experience I've found It is usually where the main harness traverses the drivers valve cover. There is a stud/bolt combination for the coil mounting bracket. The stud pokes into the harness. May not be the crank circuit, in that harness, but a lot of times 5 or 12 volt ref. and causes similar issues. HTH Sensor failure is usually when they heat up. Crank sensor failure would let you start and run until warm and then start to fall out.

[@shanestrains2849]

This is true. I had a chevy truck with intermittent A/C, 5v ref for that sensor or the return was shorting out on that same stud. Dumb luck I touched it with scan data pulled up for the sensor.

[@DJTJ13]

This has fixed 2 of these GM suvs with removing that stud. 1 on my personal vehicle and it did not hurt the wires but it just hitting the harness would cause the Christmas tree dash with limp mode. Removed the stud and have not had a issue for 2+years.

[@ScannerDanner]

Did you see me look there? I have a case study in that! I never mentioned it because my harness was still mounted and routed as it should have been which does not allow contact with that stud. Also when that happens you'll get 5v ref codes too. At least the case study I have did. Thanks!

[@michaelwitmer7536]

@@ScannerDanner sorry, must have missed you looking at that. Sometimes I get excited and comment before I see the entire video and end up with egg on my face. Just wanted to put it out there for anyone that hadn't run into it. Much respect to you Brother.

[@poq600]

Hi Paul. I guess it's time to finally change your motto: Don't be a parts changer..(UNLESS YOU ABSOLUTELY HAVE TOO). LOLOL!! TAKE CARE..

[@ScannerDanner]

Haha indeed!

[@calholli]

I've seen Ivan and Eric O both show these being bad by rust jacking. The rust will build up under the sensor and it will push it out and/or off center just enough to cause an intermittent issue. So now I always sand the surface clean before mounting them.. There's still 10 minutes of video left, so I'm curious to see what happens after the parts cannon. :)

[@ScannerDanner]

I have a case study on this too! Aftermarket sensor causing issues

[@calholli]

@@ScannerDanner I'm sure you do.. You have everything under the sun on this channel. :)

[@cliffperry8470]

Hi I’m from the uk and can I ask have you ever come across a crank sensor problem code and the vehicle is a crank no start , but if you put easy start spray in the intake the vehicle will start but not run after a few seconds. Or is that just fuel problem.

[@ScannerDanner]

I think you may be asking the wrong questions. If you have a hard fault for a crank sensor, you should be attacking that issue first. Some systems can run without a crank signal and some systems cannot. What it does with starting fluid, to me, is irrelevant, IF in fact you do have a hard fault for a crank sensor signal and no other codes. Fuel pressure can be verified separately as the pump should run for a second or two when the key is first turned on

[@cliffperry8470]

@@ScannerDanner many thanks for the reply

[@rickw.9298]

Thanks for sharing. I had a similar experience with a limp mode condition showing ref voltage low + map sensor w/ tach cutting out. Repaired map sensor wire which had a severe bend and pinch within harness and a tach wire w/micro burn through in harness at steering gear rub point. I enjoy this type of problem solving but it doesn't fit well into time and cost management guidelines. Someone always feels like it either cost too much or took too long. There has to be a better business model for this type of work. Any ideas?

[@CajunShrek]

Intermittent faults is a massive pain anyway you approach it

[@RoughRaiders13]

Could not duplicate customer issue. Have a nice day.😂😂😂😂😂

[@dkeny55]

Just wondering what percentage of the time its wiring or C/M vs the part?

[@ScannerDanner]

Every system and car and code is different! Too many variables to put a number on it.

[@apostlejohnzulu]

Hi, I am new in this business auto electrical I like the way you teach but I was left out when you were talking about safety when dealing with fuel compression and ignition system to fire.

[@ScannerDanner]

I'm sorry, I'm not sure what you mean? Thanks!

[@ThePracticalMechanic]

Plumber's pipes leak just like mechanic's vehicles have issue. Sometimes we just don't have the focus or motivation to repair our own vehicles. I started paying one of my techs to do repair work on my own vehicles since I don't seem to have time anymore.

[@philh9238]

Do you not have time? Or do you not want to? I’m the same as you. I take my car to a shop I have 0 interest in workin on it since I work on everyone else’s junk

[@ThePracticalMechanic]

@@philh9238 a little of both at the moment. I’m currently spending my away from work time editing videos and resting. Been working 50-80 hr weeks at the shop for the last couple of years. Even if I go in after hours a another tech will likely show up and distract me from getting my personal projects done.

[@AKChryslertech]

I have 3 mechanics that are customers of mine that hire me to work on their cars. Its more common than you think. They either dont have time, or arent familiar with the car or problem.

[@ScannerDanner]

Both! Lol

[@odinsclone3436]

I have a question. Ihave a 98 grand cherokee has no codes did run fine the next morning I started it it idles fine but now has a long crank time and when you try to drive it it surges pretty bad and if you Try to rev it up when it's not moving it cuts out pretty bad. Anyone have any suggestions

[@ScannerDanner]

Check fuel pressure!

[@salvadorsamora137]

I learned a lot from my uncle who worked for GALLES CHEVROLET IN ALBUQUERQUE NEW MEXICO he'd tell me all the time he never had time to work on his car's it's just like a Shoemaker fixes every one's shoe's and the poor man walking barefoot

[@richardnilsen5]

Develope and invent A new tool a mannequin that looks like danner with a scanner / oscilloscope bolted to his lap with a go pro on its head hook up the signal wires strap it in with the seat belt let your brother drive it around till the signal drops out 😁🤣👍👍👍👍great video

[@normangallant9879]

I hate intermitten problem when i was working .

[@greatreset3]

In this case, I would have used a spray bottle of water on at least the harness contact points, creating a sure short connection at a bare wet point. 👀

[@frontlinemedia4270]

Bench test the two wire crank sensor. Welcome to our world

[@ScannerDanner]

It's a 3 wire hall effect

[@frontlinemedia4270]

@@ScannerDanner I know. I want you to come up with a good test for a two wire crank sensor. Specifically that Bosch. I did resistance tests and have ranges from .63 to 1.20. I can't believe there is not a good test for these besides a scope. Not everyone has that equipment, including me. I hate being a parts swapper

[@ScannerDanner]

@@frontlinemedia4270 the problem with a resistance test is you are NOT checking the magnet or motion of the magnetic field AND resistance can test good and still be bad. So the next best test is an AC voltage output test with a voltmeter

[@frontlinemedia4270]

@@ScannerDanner I'm curious how the manufacturer test these for quality assurance. I saw a video where the technician found a Bosch cpk that was sending an inverted signal to the computer. It was a brand new part. I'm still fighting with the sprinter with a crank no start. I tested the 3 wire cam sensor like you demonstrated. I check all grounds and the fuses. I took the fuse box completely apart. I stumbled on to something after 5 days. I held the key on, and then the starter engaged. I was thinking immobilizer, key phob, you name it, but then reached and started grabbing relays. I grabbed the ecm relay and was able to make the stater turn which started the vehicle. I repeated this numerous times. I even had this relay apart 5 days earlier on a hunch to clean the 2 contacts inside but just assumed it was working because I heard a click. It clicks, but it is a delayed click. I'm not sure if it is the relay or what powers the relay. I have no relay available to swap out, so I will have to buy one or test this one first.

[@dresdensvo]

And the local parts store will sell the owner all of the sensors on that list of codes .

[@ScannerDanner]

Yep

[@shiftngearsautorepair805]

A lot of business owners run their shops based on changing parts under the prefix of a code definition. So of course every once in a while it will work, a broken clock is also right twice a day. What separates the men from the boys is when that new crank sensor doesn’t fix it. i guess thats probably why you and I both were hoping it wasn’t going to fix it 😂

[@ScannerDanner]

I was! It's still fixed BTW so it truly was a bad sensor

[@verajavi12]

No

[@salvadorsamora137]

Hay man the parts coming out now and day's R just no good I'm already used to having my costumers sin a resit that they should have just but a new part even new R coming bad it getting bad

[@careyautorepairs]

Imagine this! They added clear conduit split plastic on cars to make everybody's life more easy. Ha ha.

[@haldooley4940]

Sometimes you just have to put a part on😂

[@user-xm5qs4dj3p]

Hyundai Santa Fe 2006 code p1193

[@jgeorges3061]

hello is ur car in limp home mode that mean you can not drive the car pass 1500 rpm will not go more than 40 t0 50 klm if so this code is for ur electric throttle control check the connector and wiring first if all are good try to clean the throttle plate and air passages with throttle cleaner clean all the carbon and dirt around the plate and see hope this well help.

[@ScannerDanner]

Try typing that in a Google search.

[@user-pk8xe2hf5l]

What do we need with these stupid sensors anyway? We had engines for decades without all this BS. Let's do something to get big brother out of our vehicles!!

[@ScannerDanner]

Lol too late for that

[@CajunShrek]

Of course it wouldn't be a Chevy without a brake/abs fault

[@salvadorsamora137]

Your son has a heavy foot hill make it act up just joking I have son's and they run there car's with me in in the car but guess who they get it from