Bringing TBI and Multi Port Fuel Injection to a New Level.     EFI Conversions and Tuning! Seattle to Portland! E-mail Tuning Consultant!
Page 3 of 3 FirstFirst 123
Results 31 to 45 of 45

Thread: $EEHack Read Failure Every Time?

  1. #31
    Fuel Injected!
    Join Date
    Jul 2019
    Location
    Orange, CA
    Posts
    54
    Okay, tried the latest version and it works wildly differently from the old one. The error counts skyrocket (250 in 17 minutes, 500 in 34 minutes), but analyzing the resulting logs I no longer have any one-frame DTCs, BLMs over 18, insane knock events, or anything of the sort. It appears to be doing exactly what it's supposed to do--reject the bad data. :) I have attached the log of the drive to this post.

    In addition, the read routine now fails every single time--but does so properly. With 4.7.0 the read routine would either successfully complete and then complain about a checksum issue or would fail partway in an unrecoverable fashion that required me to remove the ECM fuse behind the battery to get back to normal operation. I tried the read function four times with 4.8.0 and all four times it got about 25% through and then hit an unrecoverable error, the program reset the E-Side and T-Side, and dropped me back to a working state as it's supposed to do. I've attached a verbose debug log of one such read attempt for reference. This still proves that there's an underlying serial data issue on my '94, but at least now EEHack is handling these errors with grace. :)

    I did notice some other bugs, but I'll go ahead and post them in the EEHack 2019 thread instead.
    Attached Files Attached Files

  2. #32
    Fuel Injected! steveo's Avatar
    Join Date
    Aug 2013
    Posts
    2,666
    awesome thanks for that testing. you've confirmed it was definitely ignoring checksums in the last version. honestly given the drastic changes in the datastream code over the last few versions, and given then fact that I did it without a test bench or a car to try it on, i'm not surprised. glad it's fixed.

    you definitely have a noisy aldl bus in that car but I wonder if it's a device that decides to keep chattering (corvettes definitely have a noisy aldl bus) i'd be curious to see if you ever find out what's up with that... if it's just a device we need to shut up, we can do that easily...

  3. #33
    Fuel Injected!
    Join Date
    Jul 2019
    Location
    Orange, CA
    Posts
    54
    Since I have the RPO sheets for both cars, I can say that in terms of features the only difference between the two cars electronically is that the '94 has the FX3 suspension and the 4L60E transmission. The transmission is handled by the PCM so that's not likely (right?), and the FX3 IIRC has its own communication that is separate from ALDL and has no ability to transmit serial data. Not to mention the problem existed before I knew that the FX3 module on my car had been unplugged, so I'm going to guess that's a red herring.

    Both cars have passive keyless entry, automatic climate control, Bose audio, dual airbags, ABS, ASR, cruise control. The '95 has a bad alternator (it whines like a supercharger) but that doesn't seem to affect the data. The '94 has bad data even when the engine isn't running anyway.

    I did go out and do testing on the grounds. Both vehicles use the OBDII-style 16-pin ALDL connector. On both vehicles, Pin 4 reads 92 ohms between pin 4 on the ALDL and the negative post of the battery. On both vehicles, Pin 5 reads a fluctuating value between 130 and 212 ohms between pin 5 of the ALDL and the negative post of the battery. This would seem to indicate to me that ground on the ALDL connector is not the issue. It could still very well be the 8192 signal wire.

    On the '95, the previous owner was under the driver's side dash to replace a brake booster. He left the footwell light unplugged but otherwise it seems to all be there. On the '94 there is no real evidence that someone has been under there, but I did notice that the ALDL connectors on each car are mounted differently. On the '94 it's mounted pointing straight down, with one bolt and one plastic lug. On the '95 it's mounted on a bracket that points it towards the firewall and is held on with two bolts. I can't be sure if this was a year-to-year difference or a clue as I only have these two cars to work with.

  4. #34
    Fuel Injected!
    Join Date
    Jul 2019
    Location
    Orange, CA
    Posts
    54
    I apologize for the double post. I decided to try out TunerPro RT for the first time. EE_Auto.adx didn't work at all. $EE-16188051-Y-body-V3.8.adx worked perfectly...or so it seemed. It connects without issue and shows 0 errors straight through. But when you go back and look at the data, you still get a few random frames of absolute junk that the program accepted as legitimate data rather than as errors. For example, ignition voltage 19.7, engine run time 60427, knock count 18437...etc. It's clear that this is bad data, but just like EEHack used to, TunerPro RT is accepting bad frames as good for some reason.

    I also tried Scan9495 v2.6.2 and it didn't want to stay connected either. It does have a verbose log generator too, so I went ahead and nabbed that. It's attached to this post. If the problem is with something on the ALDL line that won't shut up, surely there would be a way for me to listen for it and find it, right?
    Attached Files Attached Files

  5. #35
    Fuel Injected! steveo's Avatar
    Join Date
    Aug 2013
    Posts
    2,666
    since its writing over a running datastream its hard to tell which device is misbehaving but maybe we can probe a bit. ill see what i can come up with

  6. #36
    Fuel Injected! steveo's Avatar
    Join Date
    Aug 2013
    Posts
    2,666
    we had a conversation qutie a while ago perhaps involving kur4o where we talked about some b-body and y-body extra devices, but the only one that we deemed necessary to 'maybe' silence was the brake controller. i think at that time we had a list of potential devices on the lt1 aldl bus... can anyone help find that thread?

  7. #37
    Fuel Injected!
    Join Date
    Mar 2013
    Posts
    597
    That 94-95scan program is not configured for y-bodies at all. It tries to silence the f4 device, which is the pcm. On y-body the bus master is the CCM device with f1 id.

    I think the aldl is configured with 1 bus master device that can request data from other devices. All slave devices are passive and only response to request from the bus master, when needed.

    Every 1-2 seconds the bus master sends it`s ID with a broadcast ID message F0 56 [ID]
    ID can be f4 or e4 pcm, f1 CCM, f9 some newer stuff.

    It will be much easier for eehack to identify the bus master and than sends the shut up command to that ID.

    On f-bodies and some b-bodies the traction control part of the brake module communicates with the pcm to request traction spark retard, On y-bodies it is an analog setup.

    I still think it is some grounding issues or sensor noise with this particular car. Start disabling things like alternator, dashboard, pulling fuses and so on.

    You can open the raw window in eehack and do some idle scan log.


    Here are some random idle scan logs.
    Attached Files Attached Files

  8. #38
    Fuel Injected!
    Join Date
    Mar 2013
    Posts
    597
    doublepost

  9. #39
    Fuel Injected!
    Join Date
    Jul 2019
    Location
    Orange, CA
    Posts
    54
    Found the idle chatter logger thing and took some logs. Filenames are what state the car was in when the log was taken. Please let me know if there's any other test I can perform, I'll be more than happy to do whatever test is necessary to pin down this issue. :)
    Attached Files Attached Files

  10. #40
    Fuel Injected!
    Join Date
    Mar 2013
    Posts
    597
    Nothing unusual in the logs. It seems that only the ccm is talking and other modules are passive listeners, only the pcm response to the requests of the CCM. I am not sure if the CCM should talk with ignition off.
    You can try disconnect the CCM fuses and repeat the logs. Than try to read the PCM, with CCM off and make a verbose log.

  11. #41
    Fuel Injected! spfautsch's Avatar
    Join Date
    Apr 2015
    Posts
    412
    I can tell you from experience the CCM starts talking when you open a door. I've been using a FTDI board hanging on the passenger's side of the console with rx/tx leds on it for several years, and when mine's not connected to my usb hub the leds start flashing away when I open the passenger side door.

    The PKE coming into range most likely causes chatter on the aldl - mine doesn't work correctly so I have no idea.

  12. #42

  13. #43
    Fuel Injected!
    Join Date
    Jul 2019
    Location
    Orange, CA
    Posts
    54
    Here's the DS file for the 1994 Corvette CCM: http://gearhead-efi.com/gearhead-efi/def/aldl/A239.DS

    I'm currently mid-project on a drivetrain swap for a GTR which is on jackstands in my driveway, so my Corvette is in the driveway under a car cover. I won't be able to play around with it until this Sunday at the earliest. Might take until the weekend after, we'll see.

  14. #44
    Fuel Injected! steveo's Avatar
    Join Date
    Aug 2013
    Posts
    2,666
    well i don't see much good there to help with our comms but why dont we add that to the definition for the next version.... i did write multiple device support into EEHack, and it's barely been tested. there is some cool stuff in there. i wonder if it responds to any of the other commands we usually use for reflash, read ram, etc?

  15. #45
    Fuel Injected!
    Join Date
    Jul 2019
    Location
    Orange, CA
    Posts
    54
    Good question! I have some serial data apps on my laptop so I can try talking manually once I'm able to mess with the car again. I've done it just fine on Subarus and Nissans, not sure how well it'll work on a GM but I'll give it a whirl once I can.

    If we're adding definitions, here's a list of what filenames refer to what:
    http://www.totalcardiagnostics.com/p...efinitions.htm

    And here's the database of the actual GM data stream definitions once you know what's what:
    http://gearhead-efi.com/gearhead-efi/def/aldl/

    For the '94-'95 Corvette, though, these are what I've found:

    A175 ABS/ASR 1992-1994 CORVETTE
    A223 1994-1995 CORVETTE AUTOMATIC TRANSMISSION
    A239 1994 CORVETTE CCM
    A242 1994-1995 SIR/SRS
    A275 1994-1995 CORVETTE MANUAL TRANSMISSION
    A288 ABS/ASR 1995 CORVETTE
    A297 1995 CORVETTE CCM

    Unfortunately I couldn't locate a definition for the HVAC system for the Y-body, or the passive keyless entry system. Actually kinda neat though, the ABS/ASR unit can tell you how many lateral Gs your car is pushing!

    EDIT: Having a look at the service manual for the 1994 and 1995 Corvette, the HVAC is indeed tied into Pin 9 on the ALDL connector with everything else, which jives with it blinking when I try to connect anything to the line and shut everyone up. PKE however is on a totally different pin, same with FX3. Odd that I can't find a reference to Y-body C68 HVAC in the Data Stream definitions.
    Last edited by NomakeWan; 1 Day Ago at 12:36 AM.

Similar Threads

  1. First Time Posting Long time as a fly on the wall
    By Mrgto68 in forum Introductions
    Replies: 0
    Last Post: 12-17-2018, 02:00 PM
  2. Long time listener, first time caller.
    By Shameless in forum Introductions
    Replies: 1
    Last Post: 06-25-2018, 08:26 PM
  3. EEHack continuous checksum failure ???
    By kris72079 in forum GM EFI Systems
    Replies: 17
    Last Post: 09-01-2017, 12:17 PM
  4. Would Checksum failure cause these issues?
    By trippyjoey in forum GM EFI Systems
    Replies: 8
    Last Post: 10-01-2014, 11:22 AM
  5. ERROR: PROM I/O returned failure?
    By brian617 in forum TunerPro Tuning Talk
    Replies: 4
    Last Post: 10-13-2013, 03:51 PM

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •