Old guy here, when ever i come across similar codes on old vehicles i pull all major connectors and give them a good spray of contact cleaner and re-seat them all! Then go from there being in the rust belt of Michigan. Have come across many a crusty connector!!!😉 You Do a fine job at Diagnostics my friend!!!
As a professional Electronic Technician, I have found approximately 90 percent of electrical malfunctions are corrosion/bad contacts/broken wires/broken solder joints. Too often people will fire the Parts Cannon without fixing the cause first. Ivan is the Master at finding those hard to find malfunctions.
Hello. I'm a retired electrical controls manufacturer. I have made literally millions of electrical connections in my career. The thing to keep in mind is that when you make a soldered connection on copper wires it's very important that you actually make a good mechanical connection with the copper wire itself and then when you solder the wire to the device the solder itself is not allowed to flex. Solder is made with specific combinations of lead and tin and therefor has poor tensile strength thus breaking the electrical connection.
Good quick diagnostics. Good repair also. These small voltage sensors can get beat up with just a little corrosion intrusion. Thank you for showing us these vehicles on your road trip.
Remember the days when they put sensitive computers INSIDE the vehicle cab? I sure do miss those days! Nice find! I didn't know knock sensors had a bias voltage on them. Haven't had that problem come in here yet. Now I know! Much appreciated. 👍😎
I love how they not only used pot metal brake lines on this gen but also put the ABS module under the cab instead of somewhere even a little less susceptible to corrosion. As an added bonus, on the flex fuel models they stuffed a fuel filter right in front of the ABS module, making it a real joy to access when the lines inevitably rot.
@@notsureigaf Yeah, GM insanity! On my gen (GMT-900), the ABS is still out there in the open in the same location, but now the fuel pump is duty-cycle controlled, or PWM, and they eliminated the fuel filter altogether. The module for the pump lives above the spare tire, where even more water and salt can blast it to death. When that craps out, you're dead in the water - tow truck time! And when you replace it with a new $200 module, your truck still won't start - you need a J-box to reprogram the new part to your truck!! Same with your power window and lock switches. What a friggin racket GM has created. They're scumbags. So done with them.
From what I see on this and other channels I get the impression that ~60% of the electrical issues are caused by corroded/disabled power and ground connections. Just my observation based on the 10 channels I watch. Great vid, Ivan! 👍
Thanks Ivan, I thought it was the ebay sensors I bought, look Identical to the GM ones and probably are.( 04 5.3 ) Gonna go clean the crustys. Had to do the intake gaskets anyway at 212K
I had this 1993 rusted to F CHEVY K1500 truck that was a crank no start. Had a bad fusible link. After I repaired that I got a knock sensor code. Terminal at the sensor was oxidized. Cleaned it up and now it's dtc free and has been plowing snow all winter without an issue
Thanks for the tutorial you are a very good instructor. Never assume your dealing with experience mechanics that might fault you for explaining what might be obvious to them and feel the detail explanation is unnecessary because it’s not. A lot of older guys did not cut their teeth on this technology and still need to try to keep their vehicles running because they can’t afford the cost of repairs.
Turn key on, use scope test, smack side of block with hammer. Unplug harness both ends, do a test with power probe short tester injecting voltage, run tool down wire looking for break. If good then wiggle harness while running test at each end. Also on the manual knock test with scope hooked up you can use hammer while wiggling harness also. OR use the test light as you did.
Nice one ivan, i really thought the knock sensors would be bad itself as they're notoriously known for going bad on 4.8, 5.3 motors. But great fix! Deoxit to the rescue!!! Great diagnosis! 👍 many thumbs up 👍 👌
I would like to start off by saying thank you for this video. The past two months I have had serious issues with my 2000 Chevy 1500. I have had knock sensors replaced three different times from fire stone the last time I took it in they replace the knock sensor from OEM parts. After the first time they replaced it I only had the truck for two days before the light came back on. Now after having the third set of knock sensors put in the code is still coming on they can’t figure out why. So I bought a code reader and I’m able to clear the code and I’m now going to take it to a mechanic with the information that I gathered from watching your video. I now feel confident in being able to help steer the mechanic in a direction other than the knock sensor because I have a new set of knock sensors and a new wiring harness. Thank you very much for this information extremely valuable
Oh YEAH!!!! One of my favorite jobs to do!!! SUPER GRAVY as long as the sensors treads are not seized up, I've seen some really bad ones before that caused the stud to snap off, not so fun then though.
I had my own little “diagnosis” I had to do on my snowmobile… left me dumbfounded at the end of it also…. It’s a late model (2015) but has a decently complex electrical system for being a 2 stroke snowmobile (direct injection, electronically operated oil pump for the motor, and a while host of sensors and has a security system from the factory similar to a car from the 2010 era) Back story, I blew a piston last winter, so it went to the dealer to get a new oem motor w/ a factory warranty on that Picked sled up last Thursday, loaded sled into trailer after fighting to keep it running as it was out of gas… Went to start sled Saturday after dumping in a couple gallons of fresh gas, and nothing, no crank/no start (yes they can be only pull start, or have pull and electric start, but mine only has electric start from the factory). I go grab a multimeter, and check the basics right off the bat, verify volt at the battery, voltage at the 2 fuses (5amp and a 20amp) that run the sled, and check for continuity in the fuses, everything passes, I have good voltage at the solenoid also. At this point I start to have a bit of a meltdown of my own after just spending $5k on a repair to have a dead sled… and you can’t just flick a switch or key to power up the electronics to run a diagnosis on this sled unless you have the dealer harness and laptop to power up the ecm and go through a dealer diag (this would have saved my sanity if it was like the newer ones that you don’t need a dealer harness and laptop to power up the electronics) So I tear the sled apart. Checking every connection, everything is good, at this point, I say “f it” and take a wrench and jump the solenoid, and the sled fires up instantly and is running (mind is blown at this point). At this point I start checking functions and come to realize I have zero function of the start/reverse button (multi function button that the ecm takes that input when running and doesn’t let it go to the solenoid, but activates the ecm to reverse motor rotation since a 2 stroke can run backwards perfectly fine) and once I shut the sled off, zero function of the start circuit…. So this leads me to dig around on google and find a wiring diagram (in which at the point is where I made a mistake that could have saved me time) and the diagram shows. This circuit is mostly a stand-alone circuit, it has a feed wire from the battery, through the 5amp fuse mentioned earlier, heads through the ecm and back out and up the steering post the handlebars to the control block for the start/reverse, and branches to the gauge for the clock to keep time… so I take and disconnect the harness for the control block and check for continuity and can it carry a small load with a test light (hearing your voice to say check to make sure you have a reliable power and ground) and the control block tested out perfect (had I not, I was convinced from google that the control block was faulty and cost $250 to replace) So at this point I’m melting down again thinking I’ve got a bad ecm, but again I look at the flow chart, and the only thing going directly though the ecm is the “ground” side of the control block so it can sense voltage for what it needs to do, so I take test light and poke through out the harness, nothing… verify wire I’m looking for again, found it, nothing. Zero power…. So I reach down and poke the fuse with the test light, the in side lights, out side…. Dead…. Put a new 5amp fuse in and plug in harness…. And fires right up…. Pull fuse out and still has continuity but won’t carry a load 🤦♂️ So from reading more into google later, apparently being it’s such a small fuse, if you have it cranking it fires and dies and fires and dies before you let off (ie out of gas). The voltage spikes coming from the magneto are enough that when the ecm is switching from trying to run to charging to trying to run, that it going from ie 10volts cranking to 14volts running to 10 volts can shock that fuse just enough to break it without giving the classic blown fuse 🤦♂️, so it was tight enough to pass a tiny bit of voltage (I was getting .17 volts later in that harness that should be battery voltage at all times, but couldn’t carry the load to energize the solenoid or reverse function for the computer So that’s how my 2021 ended 😂
Mice go under fuse box alot on these year GMs. I had two truck s no 4wd mice ate wires under power fuse box big nest alot. Honda spice tape needed. Excellent work. PS: Ivan get " Stabilant 22" liquid from NAPA used in Aircraft it increase s conductivity on pins and connections. I used on Cranes and manlifts alot.
Been fighting this condition on my 02 for a couple years, thanks for pointing me in a direction to look,,, the shop I take (took) it to never thinks outside the box
Mine loses power upon first acceleration and on steep hills. What is the issue you were having with yours .I had my knock sensors replaced twice and still has fixed nothing
@@Mudjunkie Mine did that for about a year,, finally just quit on me after 180k,, it was the fuel pump,, nothing to do with the knock sensors,, Just had a shop replace the sensor wire/connector a few days ago, it looked burnt inside the plug,,, still getting the codes on both banks,, but the truck runs fine
@450excpilot when my fuel pump went a few years ago it lost power all the sudden. and I put it 4low to make it home. But now it only does that steep hills and sometimes that first acceleration. Just trying to figure out what to do next but I didn't even think of it being the fuel pump this time
Great advice. I had a fault on senor two. I cleaned the main wire harness plug on the sensor and with the computer connection I just moved it around and no more alerts.
Thank You for this excellent video. This showed me how to diagnose my new defective knock sensor using a voltmeter.It had the correct impedance but no ACvoltage. Not all technicians have access to scopes
Most shops you take something like this to would just keep replacing sensors. Kuddos for actually "trouble shooting"! I don't believe there's one shop in 50 that wouldn't just want to replace more parts. My favorite is the "WIring harness is bad but we can't get one" excuse.
Nice find Ivan! Seen quite a few of these with similar issues. I think my last one was a crank no start and it was so bad I had to replace the connector with a ACDelco GM repair kit. When I lifted it out the pieces crumbled onto the ground.
One of the weirdest troubleshooting things I've ever had, was an open circuit. I narrowed it down to a 8" piece of wire, and decided to just replace that. Fixed the problem (permanently ) , and I couldn't see any reason why the wire failed, so I opened the jacket. All of the strands were there. It's like, the copper just said "I quit" ..
Very nice no parts required repair. I mentioned this before but you really should have a PHAD t-shirt with "No Parts Required" under the logo. Thanks, Ivan.
Same codes I have, also last time they came on I had a miss fire (P0300) code w/them. All this started after I was getting a P0446 for evap vent solenoid. I replaced the solenoid and then got the knock codes.
Watching your videos is strictly for learning purposes at this point! We already know you’re gonna fix but it’s more of a “what can I learn from Ivan today?” kinda feeling! Always waiting for that bonus footage clip at the end! 😁
It looked like mineral deposits on the pins. Since they are gold plated they won't corrode. But that mineral gunk can cause high resistance. I use a spray and then use a small brush to knock the gunk off. Soak up whatever is left. TaDa
Years ago I had a 93 S-10 4x4 with the 4.3L. I bought it new and at about the 4 year mark, it started setting an intermittent knock sensor code. I replaced the sensor and connector with AC-Delco parts and it didn't fix the issue. I took it to the dealer and because it was intermittent, they couldn't find the problem. I never did get it fixed and eventually traded it in to the dealer on another truck. Back then I didn't know crap about trying to diagnose anything. I wonder now if it was a similar situation like what you found on this truck.
hi can you tell me what deoxit your using Hosa D5S-6 CAIG DeoxIT 5% Spray Contact Cleaner or DeoxIT D5S-6 Spray, More Than A Contact Cleaner, 142g thank you you have great video
I would be very helpful sometime to show how you use all of the wire hookups you use including the different test light sets up and when you would use one over the other
Learning to expand my diagnostic knowledge. . . 1, did you know there would be a bias voltage on the knock sensors? 2, how did you know what it should be? Or were you just looking to see if they aligned? 3, what gave you the confidence that you could feed 12v through the lines while the ecu was still plugged in? Or is that the reason for the 2 lights on each end to reduce the risk of current? Cheers Ivan. I'm loving your uploads!
Thank you for making this informational video. Having the same issue. New sensors and getting codes. now i have useful trouble shooting information. Thanks again
Ivan I have the same problem with my 2001 Chevy Silverado. Put new AC Delco knock sensor's with wiring connector in and new gaskets. Code keeps comin back?
Thank you for making this video. I do have a question though how did you connect your wire tester into the PCM where the dark blue wire goes in? I’m afraid to pull the blue wire out because it might break. Thank you.
Interesting. Need to pull that connector off and measure the output from the ECM for 18 millie volts. Also get the CRC spray. I had replaced the knock sensors before, but failed to do the torque test. Also, isn't there a ground wire behind motor that needs to be checked? I had done ohmage readings between motor and battery and found I was getting 740 ohms. Put in a small ground wire which brought it down to 8 ohms. Suspect that not enough.
@PineHollowAutoDiagnostics , @Ivan what repair software are you using in this video that you referenced at the beginning where you got the kiloohms reference information from?
Ian, community, I'm diagnosing this exact problem on my 2004, intermittent P0327. About the biased voltage you are describing -- I thought the knock sensors produced a small positive voltage themselves and sent that voltage down the harness to the PCM to interpret that voltage. Are you describing the reverse? - meaning the PCM is actually sending a 13-18mv positive voltage to the actual knock sensors with key on engine off? THX!
@@mikefoehr235 Rodents love Honda wiring. Honda even made a capscium impregnated tape for their wiring harnesses to keep Rodents away as only humans are crazy enough to eat hot food.
GM cheaps out on EVERYTHING. My '07 Silverado is a prime example. Ball joints couldn't even make 40k miles. Skipping over several failures and annoyances in between, my rear diff failed at 97k, and the transmission at 103k. Now at 117k, my engine is failing - oil pressure has been dropping off lately. Running lower than ever now. Not surprised, since oil analysis at 55k when it started burning oil showed a crap-ton of metal. Switching to 10w-30 slowed that a little, but its days are numbered. Also since day 1 there have been electrical glitches that result in no-cranks at random, and tons of communication codes. Wiggled some connections in the cab, and the problem went away for a year or so.
@@SmittySmithsonite Every Gen gets worse, I have a 04 and a 08 the 04 is more reliable at 212K than the 08 at 100K the 04 is rusty, I only drive the 08 in the no salt time of the year or I am sure it would be worse than the 04 from what I see. The08 is a VMaxx (6.0 liter max tow package) and is my summer tow vehicle weekend warrior, AFM tuned out.
Halo Mister if everything checks out fine and keeps setting the code . Can the engine be worn with 350000 miles and be setting the code with a small engine knock . Thank you sr. I have learn to much from you .
Interesting they dropped bias voltage from ~18.8mV to ~13mV post repair. Would have been interesting to have seen if you got the same ~13mV at the ECU - I expect you would. Which would mean the ECU lowered the voltage..... or something else changed (maybe based on the vehicle battery voltage or perhaps they just went into "doze" mode as the ignition was on but engine not started for a time). Doesn't seem like a great deal when figures are in mV until you consider it's a ~30% drop. Also interesting that they are in the mV range to start with!
Chilly, I would suspect it due to the first test being only one good line and after the fix it had two lines for the computer to feed a voltage into. That drops the voltage down.
@@rogermerritt6470 Thanks. My grasp of even basic electrical engineering is somewhat sub par. I think I get the relationships between voltages, current, resistance at a point in time and then someone throws in Henrys of inductance or some such having an effect - then I go down a rabbit hole of reading about inductance and impedance and my head hurts and I give up. I should go back to school to learn again from first principles somehow.
Great video as usual Ivan. I do have a question though. I have a hard time grasping the two test light concept... I usually put a test light at one end of the wire and connect the other end to ground/power depending on which was is more convenient... What more does the second test light tels me? Or is it just because you're adding a voltmeter to the mix and you want to have something to read between the two loads?
Great job of reasoning it out with a logical step by step approach as usual, one thing I still think remains Ingrained today is blame the computer, in very early days it was more often actually the problem but the industry has moved past that to the point its very very rare to see a controller failure and yet too often people start off with a presumption and then set about to quantify their original presumption rather than let the facts lead them to the true fault, I used to try to teach apprentices to let the fault tell you not you try to tell.it but alas testosterone usually led them a merry chase, great to see channels like yours and Diagnose Dan showing real world skills and processes, I wish these were around 30 - 40 yrs ago, even I google things before I get elbow deep these days, goes back to the old saying " learn by others mistakes "
Hey Ivan, any chance you would consider doing a personal review of say scanners and/or scopes? I'm shopping and it's a mess! I've noticed your ThinkTool and think I heard you mention Launch. Just a thought. You know, what you started with, which brands do you use the most and why, maybe demo certain functions where a brand stands out, which ones are pricey etc. Definitely enjoy your analysis approach! Thx
@@PineHollowAutoDiagnostics I’m going off what the mechanic said, I myself have tested the harness and the AC Delco knock sensors. Code stayed. I took it to a mechanic he did his thing for 2 days, tested the knock sensors in front of me. But is saying the circuit in the ECM is not sending or receiving voltage. That it needs to be replaced. I’m already in for $600. He’s saying the ecm is another $500. Looking for an other opinions before I spend money I don’t have. I appreciate you getting back to me thank you
Very nice diag! Had the same exact problem on one 99 Silverado I did. (I’ve done idk how many of these knock sensor replacements) they’re real good money makers no one wants to pull the intakes off. Are you aware of the GM tsb on the water redirection with silicone? Not sure how much you work on these trucks. To add on after being a Ford Dealer tech you take for granted how the new cars set codes right away and these older ones it takes multiple key cycles and or special events to trigger these codes. I was chasing a solenoid problem on my personal rig (4l60e) for a few weeks to track it down after covering the basics. Ended up with a faulty harness in the tranny and a bad solenoid probably due to excessive resistance in the harness. It was hard to track down due to the harness only having problems hot which makes diag impossible lol. I try to be thorough with my diags but that situation was unique. Always enjoy the content teaches me new stuff all the time!
The alternator winding seemed semi burned! This alternator is not long for . Seems been stressed for so long or working under full magnetic field which both are bad for alternator.
Again...crap engineering and/or materials to sensitive electronics, wires, connections, terminals etc. I reckon that manufacturers figure that their products will never see the normal road and weather conditions that exist in this global territory we have. Great fix using how electrics and terminators function. The laws of physics still rule under the hood of every vehicle.
So, first off thank you for this video. I troubleshot using your methods. And I got the following. Knock 1 = 100k ohms 15.3mV Knock 2 = 100k ohms 15.3mV Continuity verified from ecm harness to both knock sensors. If the error pops up again what could possibly be the issue?
You did state that this vehicle won't pass the NYS emissions inspection. Can the "CHECK ENGINE" LIGHT on this vehicle affect the exhaust emissions ??? Better replace the NYS. Thousands of P0327 codes are a bad knock sensor which is poorly designed and horribly located under the intake manifold. The bane of the auto industry regulated by our government.
Ivan Can you use Di-Electric grease on something like this for those of us that live in the rust belt? I know Chrysler used to use bulb grease I think Ford wanted a dab of grease in the spark plug boots on older 87 - 94 vintage F-150s so they wouldn't be DROF (you know the acroynm) LOL
Old guy here, when ever i come across similar codes on old vehicles i pull all major connectors and give them a good spray of contact cleaner and re-seat them all! Then go from there being in the rust belt of Michigan. Have come across many a crusty connector!!!😉 You Do a fine job at Diagnostics my friend!!!
im a huge fan of dialectic grease
@@ozzykrahn806 that’s to keep moisture out which is awesome but deoxit is excellent for after corrosion
You michigan folks need to get rid of whitless whitmer
As a professional Electronic Technician, I have found approximately 90 percent of electrical malfunctions are corrosion/bad contacts/broken wires/broken solder joints. Too often people will fire the Parts Cannon without fixing the cause first. Ivan is the Master at finding those hard to find malfunctions.
I had an electrical engineering professor who said "90% of electrical problems are air gap related, either too much or too little."
Hello. I'm a retired electrical controls manufacturer. I have made literally millions of electrical connections in my career. The thing to keep in mind is that when you make a soldered connection on copper wires it's very important that you actually make a good mechanical connection with the copper wire itself and then when you solder the wire to the device the solder itself is not allowed to flex. Solder is made with specific combinations of lead and tin and therefor has poor tensile strength thus breaking the electrical connection.
...dont forget pins not fully seated and not "clicked" into place
@@eastunder55 ...i would say its bad grounds
Good quick diagnostics. Good repair also. These small voltage sensors can get beat up with just a little corrosion intrusion. Thank you for showing us these vehicles on your road trip.
Another NPR diagnosis and fix Ivan! Thanks for taking us along.. Cheers!
Thanks Ivan for showing clearly how you connect leads and tool setting because for most of the people it is not always clear. Cheers!
This channel deserves more subscribers 👏
Remember the days when they put sensitive computers INSIDE the vehicle cab? I sure do miss those days! Nice find! I didn't know knock sensors had a bias voltage on them. Haven't had that problem come in here yet. Now I know! Much appreciated. 👍😎
I love how they not only used pot metal brake lines on this gen but also put the ABS module under the cab instead of somewhere even a little less susceptible to corrosion. As an added bonus, on the flex fuel models they stuffed a fuel filter right in front of the ABS module, making it a real joy to access when the lines inevitably rot.
@@notsureigaf Yeah, GM insanity! On my gen (GMT-900), the ABS is still out there in the open in the same location, but now the fuel pump is duty-cycle controlled, or PWM, and they eliminated the fuel filter altogether. The module for the pump lives above the spare tire, where even more water and salt can blast it to death. When that craps out, you're dead in the water - tow truck time! And when you replace it with a new $200 module, your truck still won't start - you need a J-box to reprogram the new part to your truck!! Same with your power window and lock switches. What a friggin racket GM has created. They're scumbags. So done with them.
@@SmittySmithsonite blah, blah, blah, blah, blah
Most computer circuits have a bias voltage
@@deerhunter8533 Nobody asked you.
From what I see on this and other channels I get the impression that ~60% of the electrical issues are caused by corroded/disabled power and ground connections. Just my observation based on the 10 channels I watch. Great vid, Ivan! 👍
Thanks Ivan, I thought it was the ebay sensors I bought, look Identical to the GM ones and probably are.( 04 5.3 ) Gonna go clean the crustys. Had to do the intake gaskets anyway at 212K
I had this 1993 rusted to F CHEVY K1500 truck that was a crank no start. Had a bad fusible link. After I repaired that I got a knock sensor code. Terminal at the sensor was oxidized. Cleaned it up and now it's dtc free and has been plowing snow all winter without an issue
You have snow this winter??
Knock, Knock
Who is there?
Ivan
Ivan who?
Ivan no parts required.
Thanks for sharing your trip and diagnostics.
Thanks for the tutorial you are a very good instructor. Never assume your dealing with experience mechanics that might fault you for explaining what might be obvious to them and feel the detail explanation is unnecessary because it’s not. A lot of older guys did not cut their teeth on this technology and still need to try to keep their vehicles running because they can’t afford the cost of repairs.
Another really tough problem solved. Ivan, you are the King! Thanks for sharing!
Great fix Ivan, I'm sure you are enjoying these stops! These videos are exciting to watch!!!
Turn key on, use scope test, smack side of block with hammer.
Unplug harness both ends, do a test with power probe short tester injecting voltage, run tool down wire looking for break. If good then wiggle harness while running test at each end.
Also on the manual knock test with scope hooked up you can use hammer while wiggling harness also. OR use the test light as you did.
Smashing diag and repair ivan 😀
I'm supprised that the module wasn't damaged by the dampness.
Lucky customer 😀
Nice one ivan, i really thought the knock sensors would be bad itself as they're notoriously known for going bad on 4.8, 5.3 motors. But great fix! Deoxit to the rescue!!! Great diagnosis! 👍 many thumbs up 👍 👌
I would like to start off by saying thank you for this video. The past two months I have had serious issues with my 2000 Chevy 1500. I have had knock sensors replaced three different times from fire stone the last time I took it in they replace the knock sensor from OEM parts. After the first time they replaced it I only had the truck for two days before the light came back on. Now after having the third set of knock sensors put in the code is still coming on they can’t figure out why. So I bought a code reader and I’m able to clear the code and I’m now going to take it to a mechanic with the information that I gathered from watching your video. I now feel confident in being able to help steer the mechanic in a direction other than the knock sensor because I have a new set of knock sensors and a new wiring harness. Thank you very much for this information extremely valuable
Did it get fixed?
Oh YEAH!!!! One of my favorite jobs to do!!! SUPER GRAVY as long as the sensors treads are not seized up, I've seen some really bad ones before that caused the stud to snap off, not so fun then though.
Ivan the man. Well done.
Another Fault By Road Salt , Good Eye On Finding It Ivan
I had my own little “diagnosis” I had to do on my snowmobile… left me dumbfounded at the end of it also…. It’s a late model (2015) but has a decently complex electrical system for being a 2 stroke snowmobile (direct injection, electronically operated oil pump for the motor, and a while host of sensors and has a security system from the factory similar to a car from the 2010 era)
Back story, I blew a piston last winter, so it went to the dealer to get a new oem motor w/ a factory warranty on that
Picked sled up last Thursday, loaded sled into trailer after fighting to keep it running as it was out of gas…
Went to start sled Saturday after dumping in a couple gallons of fresh gas, and nothing, no crank/no start (yes they can be only pull start, or have pull and electric start, but mine only has electric start from the factory). I go grab a multimeter, and check the basics right off the bat, verify volt at the battery, voltage at the 2 fuses (5amp and a 20amp) that run the sled, and check for continuity in the fuses, everything passes, I have good voltage at the solenoid also.
At this point I start to have a bit of a meltdown of my own after just spending $5k on a repair to have a dead sled… and you can’t just flick a switch or key to power up the electronics to run a diagnosis on this sled unless you have the dealer harness and laptop to power up the ecm and go through a dealer diag (this would have saved my sanity if it was like the newer ones that you don’t need a dealer harness and laptop to power up the electronics)
So I tear the sled apart. Checking every connection, everything is good, at this point, I say “f it” and take a wrench and jump the solenoid, and the sled fires up instantly and is running (mind is blown at this point). At this point I start checking functions and come to realize I have zero function of the start/reverse button (multi function button that the ecm takes that input when running and doesn’t let it go to the solenoid, but activates the ecm to reverse motor rotation since a 2 stroke can run backwards perfectly fine) and once I shut the sled off, zero function of the start circuit….
So this leads me to dig around on google and find a wiring diagram (in which at the point is where I made a mistake that could have saved me time) and the diagram shows. This circuit is mostly a stand-alone circuit, it has a feed wire from the battery, through the 5amp fuse mentioned earlier, heads through the ecm and back out and up the steering post the handlebars to the control block for the start/reverse, and branches to the gauge for the clock to keep time… so I take and disconnect the harness for the control block and check for continuity and can it carry a small load with a test light (hearing your voice to say check to make sure you have a reliable power and ground) and the control block tested out perfect (had I not, I was convinced from google that the control block was faulty and cost $250 to replace)
So at this point I’m melting down again thinking I’ve got a bad ecm, but again I look at the flow chart, and the only thing going directly though the ecm is the “ground” side of the control block so it can sense voltage for what it needs to do, so I take test light and poke through out the harness, nothing… verify wire I’m looking for again, found it, nothing. Zero power…. So I reach down and poke the fuse with the test light, the in side lights, out side…. Dead…. Put a new 5amp fuse in and plug in harness…. And fires right up…. Pull fuse out and still has continuity but won’t carry a load 🤦♂️
So from reading more into google later, apparently being it’s such a small fuse, if you have it cranking it fires and dies and fires and dies before you let off (ie out of gas). The voltage spikes coming from the magneto are enough that when the ecm is switching from trying to run to charging to trying to run, that it going from ie 10volts cranking to 14volts running to 10 volts can shock that fuse just enough to break it without giving the classic blown fuse 🤦♂️, so it was tight enough to pass a tiny bit of voltage (I was getting .17 volts later in that harness that should be battery voltage at all times, but couldn’t carry the load to energize the solenoid or reverse function for the computer
So that’s how my 2021 ended 😂
Nice! Just shows how the Ohmmeter is useless for checking powers and grounds 😉👌😁
@@PineHollowAutoDiagnostics yeah…. Would have saved my sanity if I grabbed the test light that sits right next to the multimeter 🤦♂️
Mice go under fuse box alot on these year GMs.
I had two truck s no 4wd mice ate wires under power fuse box big nest alot.
Honda spice tape needed.
Excellent work.
PS: Ivan get " Stabilant 22" liquid from NAPA used in Aircraft it increase s conductivity on pins and connections.
I used on Cranes and manlifts alot.
Been fighting this condition on my 02 for a couple years, thanks for pointing me in a direction to look,,, the shop I take (took) it to never thinks outside the box
Mine loses power upon first acceleration and on steep hills. What is the issue you were having with yours .I had my knock sensors replaced twice and still has fixed nothing
@@Mudjunkie Mine did that for about a year,, finally just quit on me after 180k,, it was the fuel pump,, nothing to do with the knock sensors,, Just had a shop replace the sensor wire/connector a few days ago, it looked burnt inside the plug,,, still getting the codes on both banks,, but the truck runs fine
@450excpilot when my fuel pump went a few years ago it lost power all the sudden. and I put it 4low to make it home. But now it only does that steep hills and sometimes that first acceleration. Just trying to figure out what to do next but I didn't even think of it being the fuel pump this time
Great advice. I had a fault on senor two. I cleaned the main wire harness plug on the sensor and with the computer connection I just moved it around and no more alerts.
Which main wire harness plug? On the manifold? Having same issue with sensor 1
Thank You for this excellent video. This showed me how to diagnose my new defective knock sensor using a voltmeter.It had the correct impedance but no ACvoltage. Not all technicians have access to scopes
Most shops you take something like this to would just keep replacing sensors. Kuddos for actually "trouble shooting"! I don't believe there's one shop in 50 that wouldn't just want to replace more parts. My favorite is the "WIring harness is bad but we can't get one" excuse.
I just paid a shop to replace my knock sensors twice and still having the same issue
Nice find Ivan! Seen quite a few of these with similar issues. I think my last one was a crank no start and it was so bad I had to replace the connector with a ACDelco GM repair kit. When I lifted it out the pieces crumbled onto the ground.
As someone who’s trying to figure out why my car acting up with same codes… I appreciate this video man. 🙏🏻 you went in deep
One of the weirdest troubleshooting things I've ever had, was an open circuit. I narrowed it down to a 8" piece of wire, and decided to just replace that. Fixed the problem (permanently ) , and I couldn't see any reason why the wire failed, so I opened the jacket. All of the strands were there. It's like, the copper just said "I quit" ..
fractured and you couldn't see it, should have crunched it and measured the resistance change.
Keith Tug Test!
Very nice no parts required repair. I mentioned this before but you really should have a PHAD t-shirt with "No Parts Required" under the logo. Thanks, Ivan.
Working on a new logo and swag as we speak! 👍😁
Thank you for the video best help yet .. fixing to check to see if this is my problem.. P0327 & P0332 .. replaced with dealership parts
did you resolve the issue?
Same codes I have, also last time they came on I had a miss fire (P0300) code w/them. All this started after I was getting a P0446 for evap vent solenoid. I replaced the solenoid and then got the knock codes.
every apprentice mechanic should subscribe to Ivan, master educator as well as diagnostic wizard
Watching your videos is strictly for learning purposes at this point! We already know you’re gonna fix but it’s more of a “what can I learn from Ivan today?” kinda feeling! Always waiting for that bonus footage clip at the end! 😁
Always appreciate your support Greg! Case study coming up this weekend will blow your mind haha 😁
@@PineHollowAutoDiagnostics Can’t wait bro! 😬😬😬
It looked like mineral deposits on the pins. Since they are gold plated they won't corrode. But that mineral gunk can cause high resistance. I use a spray and then use a small brush to knock the gunk off. Soak up whatever is left. TaDa
Awesome work Ivan. Thanks for taking us along on your adventure. How about a quick trip to Staten Island 😆.
Great Diags on the sensors and associated wiring/connectors...those crusties are a menace!!
DeoxIT, a proud sponsor of Pine Hollow Auto Diagnostics or at least they should be.
miss the staten island express happy new year
Stay tuned ;)
Thanks!
Years ago I had a 93 S-10 4x4 with the 4.3L. I bought it new and at about the 4 year mark, it started setting an intermittent knock sensor code. I replaced the sensor and connector with AC-Delco parts and it didn't fix the issue. I took it to the dealer and because it was intermittent, they couldn't find the problem. I never did get it fixed and eventually traded it in to the dealer on another truck. Back then I didn't know crap about trying to diagnose anything. I wonder now if it was a similar situation like what you found on this truck.
Nice diagnosis Ivan!
Ivan and DeoxIT for the win!
Its another GM! Whoohoo!
Your kicking butt on this road trip. I can hardly keep up with the videos.
hi can you tell me what deoxit your using Hosa D5S-6 CAIG DeoxIT 5% Spray Contact Cleaner or DeoxIT D5S-6 Spray, More Than A Contact Cleaner, 142g thank you you have great video
I would be very helpful sometime to show how you use all of the wire hookups you use including the different test light sets up and when you would use one over the other
Great idea! Key is knowing the current of each test light at 12V, and the approximate current draw of the device on the power feed.
Ivan are you going to stop off at SMA on this road trip??
Now on the "byass voltage" for the harness what setting is being used on the multimeter?......asking for a friend 😅
Next level work as always.
Learning to expand my diagnostic knowledge. . .
1, did you know there would be a bias voltage on the knock sensors?
2, how did you know what it should be? Or were you just looking to see if they aligned?
3, what gave you the confidence that you could feed 12v through the lines while the ecu was still plugged in? Or is that the reason for the 2 lights on each end to reduce the risk of current?
Cheers Ivan. I'm loving your uploads!
Those same thoughts ran through my head as well.. good stuff
Thank you for making this informational video. Having the same issue. New sensors and getting codes. now i have useful trouble shooting information. Thanks again
Ivan I have the same problem with my 2001 Chevy Silverado. Put new AC Delco knock sensor's with wiring connector in and new gaskets. Code keeps comin back?
Might be the same solution?
Does the thinktool scanner show pids for the knock sensors? I can’t find them with the Autel MS809.
Thank you for making this video. I do have a question though how did you connect your wire tester into the PCM where the dark blue wire goes in? I’m afraid to pull the blue wire out because it might break. Thank you.
Interesting. Need to pull that connector off and measure the output from the ECM for 18 millie volts. Also get the CRC spray. I had replaced the knock sensors before, but failed to do the torque test. Also, isn't there a ground wire behind motor that needs to be checked? I had done ohmage readings between motor and battery and found I was getting 740 ohms. Put in a small ground wire which brought it down to 8 ohms. Suspect that not enough.
Nice fix Ivan! The dual multimeter comparison voltages set up 👍👍Need a rat nest of wires to test the rat nest of wires lol!
@PineHollowAutoDiagnostics , @Ivan what repair software are you using in this video that you referenced at the beginning where you got the kiloohms reference information from?
I love happy endings. ;)
"No parts required". A sterling example of critical thinking and objective reasoning.
I’ve gotten to wondering, how much LSD does it take to see something pass with “flying colors”?
I see this alllllll the time with this style truck.
Ian, community, I'm diagnosing this exact problem on my 2004, intermittent P0327. About the biased voltage you are describing -- I thought the knock sensors produced a small positive voltage themselves and sent that voltage down the harness to the PCM to interpret that voltage. Are you describing the reverse? - meaning the PCM is actually sending a 13-18mv positive voltage to the actual knock sensors with key on engine off? THX!
Does GM cheap out on wiring and connectors...if so, their electric pickup will be a nightmare to own after many years.
i have 1989 gmc in salt areas. No issues only where a mouse ate a few.
@@Nudnik1 no vehicle is immune from rodents. They are vermin
@@mikefoehr235 Rodents love Honda wiring. Honda even made a capscium impregnated tape for their wiring harnesses to keep Rodents away as only humans are crazy enough to eat hot food.
GM cheaps out on EVERYTHING. My '07 Silverado is a prime example. Ball joints couldn't even make 40k miles. Skipping over several failures and annoyances in between, my rear diff failed at 97k, and the transmission at 103k. Now at 117k, my engine is failing - oil pressure has been dropping off lately. Running lower than ever now. Not surprised, since oil analysis at 55k when it started burning oil showed a crap-ton of metal. Switching to 10w-30 slowed that a little, but its days are numbered. Also since day 1 there have been electrical glitches that result in no-cranks at random, and tons of communication codes. Wiggled some connections in the cab, and the problem went away for a year or so.
@@SmittySmithsonite Every Gen gets worse, I have a 04 and a 08 the 04 is more reliable at 212K than the 08 at 100K the 04 is rusty, I only drive the 08 in the no salt time of the year or I am sure it would be worse than the 04 from what I see. The08 is a VMaxx (6.0 liter max tow package) and is my summer tow vehicle weekend warrior, AFM tuned out.
Awesome! Thanks Ivan.
Halo Mister if everything checks out fine and keeps setting the code . Can the engine be worn with 350000 miles and be setting the code with a small engine knock . Thank you sr. I have learn to much from you .
Interesting they dropped bias voltage from ~18.8mV to ~13mV post repair. Would have been interesting to have seen if you got the same ~13mV at the ECU - I expect you would. Which would mean the ECU lowered the voltage..... or something else changed (maybe based on the vehicle battery voltage or perhaps they just went into "doze" mode as the ignition was on but engine not started for a time). Doesn't seem like a great deal when figures are in mV until you consider it's a ~30% drop.
Also interesting that they are in the mV range to start with!
Chilly, I would suspect it due to the first test being only one good line and after the fix it had two lines for the computer to feed a voltage into. That drops the voltage down.
@@rogermerritt6470 Thanks. My grasp of even basic electrical engineering is somewhat sub par. I think I get the relationships between voltages, current, resistance at a point in time and then someone throws in Henrys of inductance or some such having an effect - then I go down a rabbit hole of reading about inductance and impedance and my head hurts and I give up.
I should go back to school to learn again from first principles somehow.
What diagnostic scan tool that you use in the video. Thanks
Great video as usual Ivan.
I do have a question though. I have a hard time grasping the two test light concept...
I usually put a test light at one end of the wire and connect the other end to ground/power depending on which was is more convenient...
What more does the second test light tels me?
Or is it just because you're adding a voltmeter to the mix and you want to have something to read between the two loads?
Great job of reasoning it out with a logical step by step approach as usual, one thing I still think remains Ingrained today is blame the computer, in very early days it was more often actually the problem but the industry has moved past that to the point its very very rare to see a controller failure and yet too often people start off with a presumption and then set about to quantify their original presumption rather than let the facts lead them to the true fault, I used to try to teach apprentices to let the fault tell you not you try to tell.it but alas testosterone usually led them a merry chase, great to see channels like yours and Diagnose Dan showing real world skills and processes, I wish these were around 30 - 40 yrs ago, even I google things before I get elbow deep these days, goes back to the old saying " learn by others mistakes "
Good low testosterone, Ivan!
Thank you so much that’s going to help me a lot as I swapped two sets of knock sensors god bless 🙏
Hey Ivan, any chance you would consider doing a personal review of say scanners and/or scopes? I'm shopping and it's a mess! I've noticed your ThinkTool and think I heard you mention Launch. Just a thought. You know, what you started with, which brands do you use the most and why, maybe demo certain functions where a brand stands out, which ones are pricey etc. Definitely enjoy your analysis approach! Thx
is the ohm test a sure way to know if they are working 100%?
Hello I’m having the same issue . Did that end up fixing the issue?
Would a bad ecm cause the code? Wiring is fine, knock sensors fine, but still getting low voltage codes
Unlikely. How do you know the Knock sensors are "fine"? Did you test them with an oscilloscope?
@@PineHollowAutoDiagnostics I’m going off what the mechanic said, I myself have tested the harness and the AC Delco knock sensors. Code stayed. I took it to a mechanic he did his thing for 2 days, tested the knock sensors in front of me. But is saying the circuit in the ECM is not sending or receiving voltage. That it needs to be replaced. I’m already in for $600. He’s saying the ecm is another $500. Looking for an other opinions before I spend money I don’t have. I appreciate you getting back to me thank you
Great work. Thanks.
Now the jokes and kidding.
Wire agitation score 5
Circuit testing score 10
Corrosion detection score 10
Proof of repair 10
Very nice diag! Had the same exact problem on one 99 Silverado I did. (I’ve done idk how many of these knock sensor replacements) they’re real good money makers no one wants to pull the intakes off. Are you aware of the GM tsb on the water redirection with silicone? Not sure how much you work on these trucks. To add on after being a Ford Dealer tech you take for granted how the new cars set codes right away and these older ones it takes multiple key cycles and or special events to trigger these codes. I was chasing a solenoid problem on my personal rig (4l60e) for a few weeks to track it down after covering the basics. Ended up with a faulty harness in the tranny and a bad solenoid probably due to excessive resistance in the harness. It was hard to track down due to the harness only having problems hot which makes diag impossible lol. I try to be thorough with my diags but that situation was unique. Always enjoy the content teaches me new stuff all the time!
What was the stuff you sprayed on plug on ecu
The alternator winding seemed semi burned! This alternator is not long for . Seems been stressed for so long or working under full magnetic field which both are bad for alternator.
Иван, если вдруг будешь в этой поездке проезжать мимо России - заезжай в гости))) У меня на 1zr-fe 1.6 вибрации, которые не могу побороть уже 3 года))
Maybe good to put dielectric grease around pcm connector to keep crud out ?
Clicked your video just 'cause the title made me laugh!
So did the light come back on? 😅
what website is that your using on laptop. please
Nice video Ivan.
I bet a can of Deoxit lasts a 100 years for you...LOL
Again...crap engineering and/or materials to sensitive electronics, wires, connections, terminals etc. I reckon that manufacturers figure that their products will never see the normal road and weather conditions that exist in this global territory we have. Great fix using how electrics and terminators function. The laws of physics still rule under the hood of every vehicle.
Do you want to move to the uk lol . They say the east coast is spectacular in the winter 🍺🍺🍺
Deoxit is the shit Ivan. 👍
So, first off thank you for this video.
I troubleshot using your methods. And I got the following.
Knock 1 = 100k ohms
15.3mV
Knock 2 = 100k ohms
15.3mV
Continuity verified from ecm harness to both knock sensors.
If the error pops up again what could possibly be the issue?
I'm in Philly I have an 04 suburban 1500 5.3 can I visit and get truck diagnosed
Awesome job Ivan!!
excellent find
Is there a part 2? Did that take care of the code?
You did state that this vehicle won't pass the NYS emissions inspection. Can the "CHECK ENGINE" LIGHT on this vehicle affect the exhaust emissions ??? Better replace the NYS. Thousands of P0327 codes are a bad knock sensor which is poorly designed and horribly located under the intake manifold. The bane of the auto industry regulated by our government.
Ivan Can you use Di-Electric grease on something like this for those of us that live in the rust belt? I know Chrysler used to use bulb grease I think Ford wanted a dab of grease in the spark plug boots on older 87 - 94 vintage F-150s so they wouldn't be DROF (you know the acroynm) LOL
I use Stabilant 22. It's a very thin liquid contact enhancer.
Do you like the THINK TOOL or do you need more than one scanner?
ThinkTool for everything early 2000s and up. Verus for the "classics" 90s and older :)
@@PineHollowAutoDiagnostics Thank you so much !!!!!!!!!!!!
Nice job!
Great Video Sir‼️‼️👍👍
Sir how I get service info please tell me
Knock Knock ..."whos there?" ...me
(In high voice) " nobody home"