The list shows what conditions have to met, existing codes will abort other test or the ability to re-learn. But it tells you what the system is for. All of this is enable criteria!!! The crankshaft creates constant increase in speed on power stoke and slows down evenly when not firing. This snaps shot in time is stored so that is a misfire happens, it compares to old photo to the new. If different, it uses the crank sensor to figure which two piston are on top dead center. So if different (Not actual photo, just memory) but this sets a misfire code, PO300. Once set, the PCM see a misfire, it uses the cam sensor to determine which actual cylinder is on power stroke. Now it has identified two things I'd misfire remains long enough. So the PO300 is misfire, but PO304 means cylinder number 4. It can run the test is s crank sensor or cam sensor is bad, bad wires, or not plugged in. The PCM checks each important sensor once started and can take 3 or 4 minutes. It uses voltage drop, resistance, activity to pass judgement if good or bad. Some sensors can not be checked until warm (158 degrees F) or at road speed say 60 MPH for checking an automatic for slippage inside at a gear like 3rd or 4th if one is direct drive. So engine is at 1,800 RPM, input sensor at trans is 1,800 RPM, output sensor is 1,800 no slippage. This is (OBD-II) onboard diagnostic system V-2.0. Software, sensors, scanner, information and knowledge is required to find the root cause. It breaks my heart to have a Cadillac towed from small shop with an estimate for putting in a new computer for $3,000, when 3 wire terminals to a throttle position sensor are loose, corroded or simply damaged. Then, diagnosed correctly, 3 new terminals are replaced, a little dielectric grease added, plugged in and problem solved for $90 at the dealer. Some shops that are guessing will call the parts department to see I they have a part in stock. Then ask how many they have. This is their form of diagnostics? Nope, guessing! DK, ASE master since 78, retired.
@@DallasAutoDiag Thanks but I didn't mean to go on! I am just overly passionate for best practices and increasing the image of a complex world techs live in and fix right the first time! Best of this year & 2023. Unfortunately, I am headed for a wheel chair after 3 more lumbar procedures since December to August. I'll add the to 2 bone fusions, 2 metal bars, brackets and torx head screws. One was done twice by the same Dr who never explained. But radio frequency ablation and lost count of steroids epidurals. Just strange crap as electrode trial was near perfect, they put it in a month later, went down my legs into my heels, backwards. Don't know except screwed at 6'3" and I just stay home. Sorry, not a bummer, just life! I could take most of one monthly pain med and kill an elephant. Have a better time!
@@DallasAutoDiag Thank for the kind words! Ever had a Dr call you at home? I did, and call number 4, after 7 or 8 minute in, he offered a portable morphine pump! Rechargeable, refillable and can be removed later. Unfortunately there is no recovery. But again, thanks. Over decades I have seen younger techs who had started their dream car like a Ford Falcon that haunts me. Nice kid but his car had 5 different colors, then marriage perhaps a kid. Next thing the Falcon is gone and he's in a minivan. Well, I started a 67 C10 for a family member who had to pull a trailer, starting his own mowing service. I fixed electric, put a single belt system on the 72 350 cu in, stick. After welding a few rust spots & odd holes, he quit. Gave me the truck for my work. Then entire 03 Tahoe towed into the backyard after hitting black ice & tree on passenger rear door & quarter. I had a low mileage 5.3L LS type engine. On my way to having a paid off pickup. I will keep after it, got everything I need from parts, tools but holding off on paint. I am sure it will go up in price. But we will see. Thanks!
The list shows what conditions have to met, existing codes will abort other test or the ability to re-learn. But it tells you what the system is for.
All of this is enable criteria!!!
The crankshaft creates constant increase in speed on power stoke and slows down evenly when not firing. This snaps shot in time is stored so that is a misfire happens, it compares to old photo to the new. If different, it uses the crank sensor to figure which two piston are on top dead center. So if different (Not actual photo, just memory) but this sets a misfire code, PO300. Once set, the PCM see a misfire, it uses the cam sensor to determine which actual cylinder is on power stroke. Now it has identified two things I'd misfire remains long enough. So the PO300 is misfire, but PO304 means cylinder number 4. It can run the test is s crank sensor or cam sensor is bad, bad wires, or not plugged in. The PCM checks each important sensor once started and can take 3 or 4 minutes. It uses voltage drop, resistance, activity to pass judgement if good or bad. Some sensors can not be checked until warm (158 degrees F) or at road speed say 60 MPH for checking an automatic for slippage inside at a gear like 3rd or 4th if one is direct drive. So engine is at 1,800 RPM, input sensor at trans is 1,800 RPM, output sensor is 1,800 no slippage.
This is (OBD-II) onboard diagnostic system V-2.0. Software, sensors, scanner, information and knowledge is required to find the root cause. It breaks my heart to have a Cadillac towed from small shop with an estimate for putting in a new computer for $3,000, when 3 wire terminals to a throttle position sensor are loose, corroded or simply damaged. Then, diagnosed correctly, 3 new terminals are replaced, a little dielectric grease added, plugged in and problem solved for $90 at the dealer.
Some shops that are guessing will call the parts department to see I they have a part in stock. Then ask how many they have. This is their form of diagnostics? Nope, guessing!
DK, ASE master since 78, retired.
Hey Dean, thanks for the addition. Allow me to pin your comment for the valuable information it has.
@@DallasAutoDiag
Thanks but I didn't mean to go on! I am just overly passionate for best practices and increasing the image of a complex world techs live in and fix right the first time! Best of this year & 2023.
Unfortunately, I am headed for a wheel chair after 3 more lumbar procedures since December to August. I'll add the to 2 bone fusions, 2 metal bars, brackets and torx head screws. One was done twice by the same Dr who never explained. But radio frequency ablation and lost count of steroids epidurals. Just strange crap as electrode trial was near perfect, they put it in a month later, went down my legs into my heels, backwards. Don't know except screwed at 6'3" and I just stay home. Sorry, not a bummer, just life! I could take most of one monthly pain med and kill an elephant. Have a better time!
@@deankay4434 sorry to hear that. Wish you a speedy recovery 🙏
@@DallasAutoDiag Thank for the kind words! Ever had a Dr call you at home? I did, and call number 4, after 7 or 8 minute in, he offered a portable morphine pump! Rechargeable, refillable and can be removed later. Unfortunately there is no recovery. But again, thanks. Over decades I have seen younger techs who had started their dream car like a Ford Falcon that haunts me. Nice kid but his car had 5 different colors, then marriage perhaps a kid. Next thing the Falcon is gone and he's in a minivan. Well, I started a 67 C10 for a family member who had to pull a trailer, starting his own mowing service. I fixed electric, put a single belt system on the 72 350 cu in, stick. After welding a few rust spots & odd holes, he quit. Gave me the truck for my work. Then entire 03 Tahoe towed into the backyard after hitting black ice & tree on passenger rear door & quarter. I had a low mileage 5.3L LS type engine. On my way to having a paid off pickup. I will keep after it, got everything I need from parts, tools but holding off on paint. I am sure it will go up in price. But we will see. Thanks!
This shows Your meticulous experience.keep it up..!
Thanks
Nice case study!
Thanks man. I know i owe you an answer in the other post 🙂
hello, what are the live data that should be, how can I know them?
Live data can be found in advanced scanner we use.
Good job thanks
Thank you Sir
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