In this video I try and demonstrate the usefulness of freeze frame data and code setting criteria to help find the root cause of a check engine light. In this case it was on a Chevy Trail Blazer with a P0128. -Enjoy!
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49 thoughts on “Using freeze frame data: trailblazer p0128”
  1. Avataaar/Circle Created with python_avatars twwtb says:

    Thanks man. Now I can't get that old J. Geils song out of my head.

  2. Avataaar/Circle Created with python_avatars bob palmer says:

    so if the t/s is failing will i just see the p0128? or will the coolant temp sensor cause this code if it fails and no other codes?

  3. Avataaar/Circle Created with python_avatars FSU 378 says:

    Man I wish they would have kept that thermostat in that location!!! My 2008 has it at the very back passenger side of my inline 6! It. Is. Freakin. Pita to get to. Big time!

  4. Avataaar/Circle Created with python_avatars Chuck Grenci says:

    Did a thermostat on my '04 Bravada (same engine, etc.) about three years ago as I had the same code (low mileage vehicle at approx. 62 k at the time). Recently got the same code (P0128), at 83 k, so this time I changed the coolant temperature sensor (and I know I should have changed the thermostat again) but I was curious to see if my temp sensor was the real culprit. So far, no code, but I guess time will tell. Oh, changing either is a big pain in the tookus(sic); behind the alternator, which isn't any fun either. Hope I don't have to go in there again. 😀

  5. Avataaar/Circle Created with python_avatars Sean Seann says:

    Good information………..what model autel are you using

  6. Avataaar/Circle Created with python_avatars Christopher Pinto says:


  7. Avataaar/Circle Created with python_avatars Sarah Sargent says:

    Very helpful,well explained,good use of logic,and experience =right repair 1st time,good video,thankyou.

  8. Avataaar/Circle Created with python_avatars throttle bottle says:

    I'd assume the run time is in seconds, so 1 second short of 9 minutes of pure yeehaw going nowhere fast and burning through fuel :))

  9. Avataaar/Circle Created with python_avatars 8power0 says:


  10. Avataaar/Circle Created with python_avatars Nater Salad88 says:

    What scan tool is this? Im looking at buying an Autel scanner that has bi-directional controls, calibrating capabilities for after repairs like throttle bodies etc. , true live data, etc. We dont have a snap on truck or mac or matco that comes out to shop so looks like Autel is gonna be our route through the local NAPA. We use a laptop based cummins program for a scanner on school buses but now need to add a scanner for everything else thats getting added to our fleet from duramax's, explorers, powerstroke pickups etc.

  11. Avataaar/Circle Created with python_avatars Scott A says:

    Thanks for the video Eric!  I have been getting the same code on mine intermittently.  I was 99% sure it was the thermostat and with this I am able to confirm it!  I am almost positive mine is the original thermostat with 195K.  Just got the TB so time to change it!

  12. Avataaar/Circle Created with python_avatars Omar garage says:

    🖒 buen dicho yo puedo hacerlo tu puedes hacerlo🖒

  13. Avataaar/Circle Created with python_avatars Evnflw1 says:

    Dude. Love the channel. I think you’re a great mechanic. I’m watching too many vids. I got the old lady’s car in pieces every weekend. Love it !!

  14. Avataaar/Circle Created with python_avatars matthew1992ya says:

    it seems that while using the otc scan tool you often have to change scan tools if that doesn't answer some of the what scan tool to buy questions I don't know what will

  15. Avataaar/Circle Created with python_avatars ncrdisabled Submarine vet says:

    Harbor freight has a new scanner for 2k they say it good as a snap on

  16. Avataaar/Circle Created with python_avatars Papi-Champoo says:

    The Bob Ross of automotive stuff.

  17. Avataaar/Circle Created with python_avatars Evans Autocare evans says:

    eric o. this is what we have to deal with

  18. Avataaar/Circle Created with python_avatars Kent Schroeder says:

    So the computer is my friend if only I were able to hear and see what is telling me, hence the Autel.

  19. Avataaar/Circle Created with python_avatars RJ_Make says:

    Freeze Frame…… Reminds me of a song I once …….

  20. Avataaar/Circle Created with python_avatars Snake Skin Productions says:

    I use freeze frame data all the time. Also, thank the automotive powers that be for giving us "Identifix. I find it real helpful when I get into something that I have not worked on before. Nothing like the experience of other techs which is one of the reasons I watch your channel. Minds are like parachutes, they only work when there open. Thanks my friend…

  21. Avataaar/Circle Created with python_avatars Alex Olivera says:

    Good video amigo.

  22. Avataaar/Circle Created with python_avatars Chris VanKauwenberg says:

    I do look at freeze frame data depending on the situation. I appreciate your perspective, thank you.

  23. Avataaar/Circle Created with python_avatars S & A Auto Repair says:

    Next up, a video where the freeze frame has zero helpful information. Cause I love when that happens

  24. Avataaar/Circle Created with python_avatars bobl78 says:

    Distance since first failure  58 miles, Distance since last failure   637 miles… here we are again with which scan tool is the best 🙂

  25. Avataaar/Circle Created with python_avatars bobl78 says:

    what happened to the "Hello viewers and welcome back… ???

  26. Avataaar/Circle Created with python_avatars 2009 G8 GT 6L says:

    This happened to me with my GM Oh and it was caused by me also. I was experimenting with different thermostats and when I stuck the 170 in it. Well lets say it wasn't happy.

  27. Avataaar/Circle Created with python_avatars Josh Thomas says:

    Well there’s your problem! Great advise!

  28. Avataaar/Circle Created with python_avatars Justa Hasbeen says:

    What if it was -40 out? The temp might never get to normal 😉

  29. Avataaar/Circle Created with python_avatars Dylan Keen says:

    I despise Bosch scanner software. Be Mac, otc or whatever. No thank you

  30. Avataaar/Circle Created with python_avatars LMacNeill says:

    8 minutes, 59 seconds is 539 seconds, just FYI. 🙂

  31. Avataaar/Circle Created with python_avatars Stephen Peralta says:

    Hi Eric, do you know if there is a place to find the same kind of code setting criteria for the DIYers? I noticed that you used Identifix to find that information. However, not sure that is a viable option for the diy guy. Thanks!

  32. Avataaar/Circle Created with python_avatars Alan Matthews says:

    I understand why you can not suggest only one brand of diagnostic scanner. Thanks Eric.

  33. Avataaar/Circle Created with python_avatars Mrkt trdr says:

    Thanks for the knowledge, now
    Let's see the actual change of thermostat always like seeing the mechanical process

  34. Avataaar/Circle Created with python_avatars Mechanic Technician Repair says:

    A question the escaner is already includes witn the electronics diagram

  35. Avataaar/Circle Created with python_avatars Harmony Hollow Apiaries says:

    Not necessarily freeze-frame data – but I use FORScan with my 2001 F250 7.3L for live data to monitor HPOP pressures and more. Also good for injector buzz-tests.

  36. Avataaar/Circle Created with python_avatars Tim Wrenn says:

    thanks for the info! you can learn something new every day if you have an open mind!!

  37. Avataaar/Circle Created with python_avatars mb houtex says:

    So wha happen to "Hey there viewers, and welcome back to the South Main Auto Channel!"? Been missing these last times…

    I know, I know… busy things, setting up and all that… it's just kinda comforting is all…

    Oooh, I know! Maybe pick your best "Hey there!" from a previous show, throw it in front, then play Big Nasty's music while your logo fades in, then use Brake Cleaner fanfare on a hard cut switch to you and the new video!

    …or… not… I guess… I mean, I understand if you can't…


    Keep doing the great work you're doing, and ignore me. I'm used to it by now… XD

  38. Avataaar/Circle Created with python_avatars Baxrok2 says:

    Definitely an important diagnostic resource. Thanks Dr. O!

  39. Avataaar/Circle Created with python_avatars Smitty Smithsonite says:

    I've had quite a few Ford 3.0 DOHC engines with vacuum leaks (intake), where freeze frame data told the tale. Misfire city – freeze frame says, coolant temp: 59° – runs better with heat – then confirmed with the water test. Bingo! Longest part of the diag is waiting for the damn scan tool to stop the "spinning wheel" thing and get down to business! 

    It's 2019 – can we get a damn magic-box computer that works FAST??? Is that too much to ask?!? 😡

    GREAT vid, Eric – you say you're not a great teacher … I say … BS !! 🍻😊

  40. Avataaar/Circle Created with python_avatars roadkill5333 says:

    I love freeze frame data!! As a matter of fact, I had a bowl of them for breakfast just this morning! With sausage links and orange juice! Lol

    I was visiting a friend once. A family friend of his was present, and mentioned that she wanted him to change her thermostat. I asked why she just needed a thermostat changes, was she overheating. She said no, just the opposite. She was getting the dreaded P0128. Well of course, I had to look it up. I'm not as smart as you guys are. And I came up with the same thought. This could be an issue. Then she tells me that was the problem last time!! Huh?? Beg your pardon?? Did you say last time? She said that this happened a few weeks ago, too! And she changed the thermostat, and the code went away. UNTIL NOW!! I was like "AH HAAAA" well there's your problem right there, lady!! But, I was outnumbered, one woman to only two guys!! We changed her thermostat! I whispered a few times that this wasn't the problem, to the friend, but her just shrugged, and said we have to do what she wants!! I just assisted, and watched, while it all was done. She brought a T-stat, with her. NO COOLANT! No bucket! No drain pan, nothing but the need!! After the NEW coolant was drained into the street, they went for other NEW coolant. Someone asked what was up, and I explained that she saw a code, and wants someone to shoot the parts cannon at it. So, we were the ones to do it. While they were gone, I got a little curios, and grabbed the old(NEW) T-stat, and looked it over! What should appear before my very eyes?? Why, that was a large gap, where a large gap shouldn't be! Seem like the old(new) T-stat was faulty after all!! And allowing a pretty good amount of coolant to flow, keeping the engine a bit too cool, for a bit too long. Who'd a thunk it?? I set it back down, and went inside. They came back, and went went to refilling the system, while she tidied up a bit. As I walked out, I saw her throw a 20 footer across the driveway, and the old(new T-stat dropped home, NOTHING BUT NET!! I jumped immediately into action, and told her to back the truck up. I retrieved the old(new T-stat, and pointed out the obvious fault! I explained that she out to return it, to the store for a refund, and show them this. I reached for the box for the new(new)T-stat, and put it inside, and said she could maybe get a refund, if she has the receipt! So, she was right all along, the old(new)T-stat was faulty, and causing the code to set, again!! I had to eat some crow, but I think it taught me a lesson. It also turns out that she was employed at the very company where she purchased that faulty part. She works in the warehouse, not the parts counter. But still. She got her money back. One of those times that you ask yourself, O, O, O, O'REALLY?? wink wink

  41. Avataaar/Circle Created with python_avatars geoffrwelsh says:

    Eric, I vote for more factory tool usage. Autel and OTC have their own YouTube channels.

  42. Avataaar/Circle Created with python_avatars Steven Almendarez says:

    Outstanding video.

  43. Avataaar/Circle Created with python_avatars Robert Evans says:

    Very informative…Dr O

  44. Avataaar/Circle Created with python_avatars Joe's Auto Electric says:

    Eric you have a gift to get a point across man. Very nicely done.

  45. Avataaar/Circle Created with python_avatars DrD says:

    Could it have been the coolant temperature sensor itself? (I am sure the statistics don't lie, but if it were the ECT that was failing/out of spec, would the data have been different?