Silverado Cranking When Turning the Key Off 

You outsmarted the joker that left the info out of the service info. Great job figuring out and explaining how the ignition switch and BCM work together to crank the engine.

Diagnostics with aftermarket garbage found as the cause should be an EXTRA charge. This should be a thing, lol. World class diags!

Scope visualize the fault perfectly. Great. Thank you Jake.

Nice! Negative Parts Required is always a win 😁👌

Years ago, I figured out to always look for something that didn't belong from the factory before I spent the time to look for a problem. It always proves me right

Your knowledge of using overlay in your diagnostics is incredible. Drawing red lines and forming boxes over the circuits really helps me follow along better. I'm more used to trouble shooting with schematics that have the reference signals and voltages under a diagnostics loop

Excellent troubleshooting. First thing I did to my grandkids cars was to rip that aftermarket crap out when fixing a electrical issue. Hint: To make that Fluke meter respond faster, take it out of auto scale mode. In manual mode the meter does not have to think to determine the required range.

You never cease to amaze me. I have learned so much from you and I can't thank you enough.

I had same problem 6 months ago. Used car lot just wanted to replace ignition switch. After that didn't work they approved diagnosis. Remove add on part and problem fixed.

This one is a nice scope tutorial, me and my multimeter wouldn't figure out that ,I really need a scope ,thanks for that one

Man this was a terrific case study! Very interesting process to dial in the issue. Lots of techs would have thrown a switch at it…

We learn a lot from you. Greetings from Iraq

Great Diag. You're the man! ;) It shows how important it is to have a wiring diagram that has all the info. You figured it out when you had the entire diagram where when you only had the first diagram it could have thrown you for a loop. Awesome find and great thinking.

People think an ignition switch is an ignition switch like seen years ago handling 12V when now all it is is a sensor handling a low ref voltage and sending a signal voltage to BCM so it can control the real ignition switch-the run/crank relay and that relay is the real ignition switch for loads to be wired to. Thanks for sharing.

GREAT VIDEO as always . Man you are right there with Eric and Ivan in my eyes. Love the videos man keep them coming

So, service info did not show that part of the operation. Your thought process with the wiring diagram and the scope proved how it worked, and the 194 bulb proved the problem. Your experience with aftermarket items found the root cause of the problem. WOW! That aftermarket part would have contributed to a starter motor shortened life span. Great Diagnostic Jake! Thank you for this video.

JAKE, YOU ROCK BROTHER AWESOME APPROACH AND THOUGHT PROCESS TO DIAGNOSE TODAYS CAR A SCOPE IS MUST IN MY OPENION GREAT VIDEO THANKS FOR SHARING CHEEEEERS FROM CANADA.

Test light was a good call, I liked that.

You got your hands full on this one.

nice. i love these electrical studies. gives us newbs a change to reinforce the electrical basics through YOUR eyes and hands. I only fix my own and luckily (Or unluckily) I've never had an electrical issue with my 3. only boring brakes and door-handles... The wife did say her power seat stopped going forward for a few days, maybe I can convince her I need a new 4 channel Pico to fix it...

Great case study! I admire your patients to actually diagnose it and not first pull out all the aftermarket stuff.

Awesome always learning something on this channel

Great job. I like the way you think things thru. I always learn something from your videos.

There is no doubt this is a hard diagnostic routine. Dealing with battery voltage, reference voltage, and voltage drop at the ignition switch.

you get the craziest faults, wish I could get stuff like this to play with and learn

Very impressive diagnosis and explanation of the start circuit. Being a retired 50 year car wore veteran, my Las few years was working service at a used car dealer. We got lots of junk auction cars with crazy issues. I had no fancy equipment to work with. I barely had a working scan tool. But my go to was looking for aftermarket garbage. Most of the time that was the failure. Backup cameras and remote starts. When they get old they become failure points for sure. Great work! I love your videos along with Ivan's. You both have a bit of Howndog bred into you!

Another weird case! I immediately said "it's the ignition switch", as worn out ignition switches can do crazy things, but that only lasted until I saw the second scope line, showing some capacitance holding the voltage. Very clear minded analysis, Jake! And without the scope and your rational thinking, there would be parts thrown at it. Very interesting and cautionary video!

You shining in every diag❤❤❤❤❤

Superb ! This was a great diag and total explanation Thanks

Excellent work!

Well done 👍

Awesome Diag as always and thank you for walking us through how you think during the whole process .

Excellent video, sir!

Great case study

Great job

nice work!!!!!!!!

really smart approach

Awesome diagnosis! Thanks

Good video. Thank you for sharing

Excellent video

Great thought process Jake

Excellent video and explanation as always. Another great simple one.

great diagnostic , smart logic good job

The first thing that comes to mind is a stuck or pitted starter relay. Watching till the end. Thank you

GOOD ONE,,,,,,,,,,,,,,,, THANKS FOR YOUR TIME !!!!!!!!!!

Great video. Enjoyed the illustration and visual when using the wiring diagram. Thanks for your time and effort.

yeah, I was ready to replace the ignition switch when you were.

modified the circuit till it broke lol sweet diag 😊😊👍👍

Nice find! Great thinking process! Above and beyond the capabilities of most technicians today. I'm sure with experience, you could just go looking for something aftermarket and cross your fingers, but to prove it before hand is top notch! Thanks for sharing!

sloped voltage is almost always a discharging capacitor. that dropping out so far down then sloping could have also been a zenor diode. remember when manufacturers would put an accessory location on the fuse box? hmm maybe a reason why they dont any more. if that item wasnt so cheap they could have added a diode and a bleed resistor it wouldn't have been a problem

Wow, I thought straight Swatch, well done, thank you

Was thinking that the after market accessory causing a counter efm from a relay. Thanks, the old school guy

Jake this video kind of teachers all of us that when a vehicle displays weird electrical issues the first step in fixing the issues look to see if there is anything installed that didn’t come with the vehicle to start with. Is this a car lot vehicle and wonder how long its had the problem? I would kind of think it would show up as soon as the wires were tapped into. What were those extra wires powering? Any way thanks for sharing Jake I know I learned an important troubleshooting step. 👍

Dam good job Jake . Soak him good.i had a viper alarm put in my new dodge p up I picked it up and the abs like stayed on I told the cs to take it out right away and the light was out. Those alarm guys tap in to any thing that's got power. Ps happy father's day .sam

Great video and case study. I don’t know how many times I have taken off leftover wiring after most of that old system had been removed. Aftermarket car alarms seem to be the worst offenders since they tap in all sorts of places. It’s always great when you can fix it by taking something off. 😂😂

🤣 I didn't get that....Could you try again.! Lol Geat diag Jake. Taking the time to further investigate the logic of that switch and then obviously once again, the power of the lab-scope to proved out the issue. Honestly, I thought it was going to be someones aftermarket auto start crap before you even went there with that rear view camera junk. Again...Awesome find and great captures of how that circuit works. 🤩👍

That was cool

oh yes how does it work and what does it want 👍 . interesting for history in the truck like when did it start doing it or if it’s been like that since they got it

excellent. no parts required

Nicely done! Beautiful example of "test, don't guess." If you wanted to keep that aftermarket module, adding a diode in series with the unit would fix the issue, keeping the capacitor from draining back into the ACC line. Manufacturer was evidently too cheap/dumb to do that.

Grasias

My daughters Honda Civic had an aftermarket remote start and it was starting her car during her work day when her remote starter remote control was 20 miles away at her house. I found the controller sending a signal when it picked up a signal from a short in the wiring (scotchlok connections). I disconnected the remote start and she had her gas mileage back to normal and her engine only ran when the original equipment ignition switch said it should.

Master

Great job finding the source of the problem. I would think any aftermarket component should have its own circuit created from the battery directly.

I worked at a body shop / used car lot for 10 years and removed hundreds of aftermarket garbage causing all sorts of problems

It remembers my 87 Sentra it keep running for a few seconds. Nobody was able to figured why.

❤❤❤❤❤

Your meter is fast enough... just take it out of autorange and into manual range 60. Then you see everything from 0 to 60V. At the end this is a 6000 count meter.

❤

Time to consult the owner. When I was working on cars and trucks if the vehicle was equipped with an after market remote start system I generally refused to work on it. Of course this was in a flat rate shop.

That was a serious diagnosis, well done on that. It can be really hard to understand what is going on with modern cars even with the diagrams. Great video 💪💪💪💪

👏👍

That resistor is probably a limiting resistor in conjunction with a capacitor thats wasn't drawn in the wiring diagram. Having a schematic of the ecm and that ignition circuit with reference voltages or reference signals would help greatly. I know wats wrong it it ain't got no gas😂🤣 or it ain't got no ground 🤣😂😂😂

It’s the black box on the backside of ignition messed up my ford did that

Jake, nice find !!…did you ask the owner if he had ANY aftermarket parts or wiring in this case done to the car ??

So the BCM must see approximately 4V to start the starter?

People and their friggen add-ons and they think if a wire is hot I can tap right there. Not realizing a lot of times it's being monitored. I guess what a fellar needs to do first thing is do a visual check and look for after market shit! But a better question would be just how to charge for something like this? I don't know how much time you actually used but I'd charge for it all!

That looks like an arcing waveform to me similar to ignition.. maybe bad capacitor

I once fixed a 2014 equinox that would randomly crank the engine without a key in it.

Where are you located?

Jake when Ivan says place your bets now he would bet the farm on you and I would to Artificial intelligence can't fix it but real intelligence can Nice logical work Jake 💯

Somebody fiddled so cut the string.

Uncle Berny say As usual always aftermarket bs 😂

I'm wondering if it's happen in same time they fixed this garbage aftermarket stuff

Always some kind of aftermarket garbage.

Probably one diode will fix that problem.