Page 6 of 7 FirstFirst ... 4567 LastLast
Results 51 to 60 of 62

Thread: Why no DSP for LML?

  1. #51
    Junior Member
    Join Date
    Jan 2010
    Posts
    10

    Default

    Quote Originally Posted by Road View Post
    There is a lot more than just changing one table to make switch control the fuel rate. You don't have to use fuel temp sensor either you can use IAT, EGR temp, etc any sensor that ecm needs less would be best. You will need to edit several axis and disable some bits and then turn off diagnosis for the said sensor. Then you will need to have a switch that is capable of controlling the resistance and no one switch works with every method. So that being said there is many ways to control fuel rate and a working setup takes a lot of time to make it work and be reliable. There is way more involve than most know and requires little more than a cax file that's why you only see the best of the best offering it and very seriously doubt they will share their hard work.
    I did some more searching on the B0457 table and it sounds like that is that table being used. We can currently buy the switch with instructions on how to pin into the ECM. I'm just not sure of the axis within that table for each "tune". I now understand that it is simply a limiter and not an actual DSP tune.

    I did ride in an 2016 LML with the switch and a well know tuner's file. It does feel like it has 5 different tunes in it, not quite like my 03 LB7 or 06 cummins (both have DSP and CSP switches) but if you didn't know any better you would think it had a DSP5 switch.

  2. #52
    Lifetime Member DURAtotheMAX's Avatar
    Join Date
    Nov 2005
    Posts
    1,016

    Default

    Quote Originally Posted by dpc View Post
    I did some more searching on the B0457 table and it sounds like that is that table being used. We can currently buy the switch with instructions on how to pin into the ECM. I'm just not sure of the axis within that table for each "tune". I now understand that it is simply a limiter and not an actual DSP tune..
    Thats what you'll have to figure out, trial and error....unless you can find someone to tell you.


    Quote Originally Posted by dpc View Post
    I did ride in an 2016 LML with the switch and a well know tuner's file. It does feel like it has 5 different tunes in it, not quite like my 03 LB7 or 06 cummins
    Thats because its only pseudo "tune switching". It's somewhat "close enough" to give most people the impression that its "switching tunes"....but for more discerning people who know better, they can tell that its just modifying max allowed mm3.

    The version of "SOTF/DSP" that I made used CAN messages and actually changed/commanded which pedal to torque and fuel maps the ECM used...so it was actual mode switching, albeit near as expansive and fine-tunable as true EFILive DSP.

    But my method was much much more complex to implement, thats why I never was able to fully release it besides the dozen or so trucks running around with it. Its too bad I ran into mass-production snags though, because I did like how it was all controlled via the driver info center and factory tapshift buttons.

    Ben
    2005 Silverado, CC/SB, 4x4, LT, LILLY/Allison
    12.9s @ 108 mph

    many thanks to Ross and Paul

  3. #53
    Lifetime Member DURAtotheMAX's Avatar
    Join Date
    Nov 2005
    Posts
    1,016

    Default

    Also, on the fuel temp sensor SOTF...

    There are several other changes required that are outside of what EFILive has mapped in their tuning tool.....

    1. You have to enable "fuel temp sensor 2" on the 2012+ OS's. Because only 2011 trucks had two separate fuel temp sensors from the factory. 2012+ it was unused.

    2. You have to change the scaling of the measured-voltage-to-temperature table for the fuel temp sensor #2. Basically what B0212-B0213 does in an 01-05 LB7/LLY tune file. Note I said 01-05 LLY. You wont find B0212-0213 in an LML tune because EFILive does not have it mapped.

    3. You have to disable range-extension of the fuel temp sensor. The ECM has a forward-biased pullup resistor inside it with a little FET in there that can change the value of the pullup resistor on the ADC input of the fuel temp sensor circuits. Obviously all ADC inputs to ECU's have to have either a somewhat high-impedance pull up resistor to +5volt reference, or a pulldown resistor to low-reference. Otherwise the ADC input would float erratically and not give accurate readings. Its also buffered with an op-amp in voltage-follower configuration...but I digress.

    Anyway, the IAT and ECT sensor inputs have this feature too. Its to give the sensor more accuracy throughout its range of -40* to 300* or whatever. Think of it like high range vs low range in a transfer case. Around 130* or so, the ECM triggers the FET to change the pullup resistor value so now instead of the thermistor referencing a 10k ohm bias to +5v, its using say 5.6k pullup value.

    If you dont disable the range switching, when you change tunes to the point of the ECM reading around 130*, it'll switch that internal FET and the readings from your DSP switch will then get all screwed up and it'll jump from like 130* to 200* or something. Then your B0457 table becomes all wrong again.

    Or I guess you could also just carefully tweak sensor scaling range 1 table and sensor scaling range 2 table independently so even when it switches ranges, the measured temp value is overlaid/corresponds properly despite the shift in pullup bias....but thats probably more of a pain.


    The rest of the stuff you need is right in EFILive. B0457, and the axis modifier tables....because B0457 only goes from like 220-260* or whatever, you need to broaden the range to give a greater difference in the fuel limiting factor value.

    2015-2016, there are a couple extra things you have to do....you cant directly copy-pasta all changes from 2011-2014 OS to 2015-2016.

    Its not rocket surgery, I messed around with this "DSP" method like a year and a half ago and it worked alright...but I didnt know as much about working in the LML binaries back then because I didnt own an LML until october 2015, so Id never worked on them before....so I wasnt able to figure out how to disable the sensor range-extension feature....so I had to make a complex DSP switch with some extra logic in there to compensate and change its outputs at the same time the ECM changed the pullup value. If I had all of the LML documentation and A2L, it would have been easy-peasy. The concept is simple as hell.

    But I abandoned the EGR temp/fuel temp sensor based "DSP" because I never liked the idea of sensor-fooling just because its not true mode switching, I think its kinda ghetto/hack...but thats just my own stupid opinion. So I pursued my CAN-based method that actually commands the ECM to change modes and put all my eggs in one basket with that. Yeah, it was probably dumb of me to do that, should have kept the EGR/fuel temp based "DSP" and just said "screw it, good enough, uses existing DSP switches, inexpensive, works alright"....but whatever, thats because Im a true out-of-the-box tinkerer/engineering-design nerd and NOT a business man.

    Ben
    2005 Silverado, CC/SB, 4x4, LT, LILLY/Allison
    12.9s @ 108 mph

    many thanks to Ross and Paul

  4. #54
    Senior Member
    Join Date
    Dec 2015
    Posts
    126

    Default

    So on CAN...

    If there is a way to control the mode it would be done with the quote unquote 'Device Control'. Which for the LML's ECM would be a command that looks like 7E0 08 AE aa bb bb bb bb bb, where AE is the mode, aa is the the control mode, and the bbs are the data for that control.. Also the length is always going to be 8 bytes, because Bosch. You know it did something if you didn't get a 7F.

    Additionally you will need to send this to to the ECM about once every .5 seconds or so, else nothing will work. 7E0 01 3E(just the ecm), or 101 FE 01 3E (everything).

    Also sending 7E0 02 10 02 or 101 FE 02 10 02 after you start sending the 3E would be a good idea as well. When you send the 3E signal trouble codes get disabled among a bunch of things, the 10 signal will undo most of that.

    I doubt the ECM listens for a mode change on anything other than 7E0 08 AE blah blah blah. Wouldn't make sense really. They use this same system in the OEM tuning of the engine.

  5. #55
    Lifetime Member DURAtotheMAX's Avatar
    Join Date
    Nov 2005
    Posts
    1,016

    Default

    Quote Originally Posted by Snipesy View Post
    So on CAN...

    If there is a way to control the mode it would be done with the quote unquote 'Device Control'. Which for the LML's ECM would be a command that looks like 7E0 08 AE aa bb bb bb bb bb, where AE is the mode, aa is the the control mode, and the bbs are the data for that control.. Also the length is always going to be 8 bytes, because Bosch. You know it did something if you didn't get a 7F.

    Additionally you will need to send this to to the ECM about once every .5 seconds or so, else nothing will work. 7E0 01 3E(just the ecm), or 101 FE 01 3E (everything).

    Also sending 7E0 02 10 02 or 101 FE 02 10 02 after you start sending the 3E would be a good idea as well. When you send the 3E signal trouble codes get disabled among a bunch of things, the 10 signal will undo most of that.

    I doubt the ECM listens for a mode change on anything other than 7E0 08 AE blah blah blah. Wouldn't make sense really. They use this same system in the OEM tuning of the engine.
    My method does not use $AE device-control messages.
    2005 Silverado, CC/SB, 4x4, LT, LILLY/Allison
    12.9s @ 108 mph

    many thanks to Ross and Paul

  6. #56
    Lifetime Member DURAtotheMAX's Avatar
    Join Date
    Nov 2005
    Posts
    1,016

    Default

    Snipesy the stuff you are referring to is basic OBD scan tool protocol, the $AE, $7E0, rejected request, $01 #3E, etc. Its not anything special. Every vehicle uses that stuff for UUDT/USDT scan tool communication.

    And the fact that the messages are 8 bytes is "because CAN".....not "because Bosch".....
    2005 Silverado, CC/SB, 4x4, LT, LILLY/Allison
    12.9s @ 108 mph

    many thanks to Ross and Paul

  7. #57
    Senior Member
    Join Date
    Dec 2015
    Posts
    126

    Default

    Quote Originally Posted by DURAtotheMAX View Post
    Snipesy the stuff you are referring to is basic OBD scan tool protocol, the $AE, $7E0, rejected request, $01 #3E, etc. Its not anything special. Every vehicle uses that stuff for UUDT/USDT scan tool communication.

    And the fact that the messages are 8 bytes is "because CAN".....not "because Bosch".....
    Hey Im trying to help. It is special GM specific nonsense. Yes it is the GM 'standard scan tool protocol' but is that not what you want?

    If you want more you'd need dedicated boxes to repeat other modules. Let the ECM operate in your own world. Which hey, if you can do that lemme just say there are many other fields which could use you.

  8. #58
    Lifetime Member DURAtotheMAX's Avatar
    Join Date
    Nov 2005
    Posts
    1,016

    Default

    Quote Originally Posted by Snipesy View Post
    Hey Im trying to help. It is special GM specific nonsense. Yes it is the GM 'standard scan tool protocol' but is that not what you want?

    If you want more you'd need dedicated boxes to repeat other modules. Let the ECM operate in your own world. Which hey, if you can do that lemme just say there are many other fields which could use you.
    Im not sure what you're getting at? Kinda confused, sorry haha.

    I am not sending the ECM "scan tool commands" to make it change modes, its something else that I figured out.

    Believe me, I wish there was a simple scan tool command ($AE) that would make it change modes! Maybe there is, I dont know...maybe you could command a service regen and that would put the ECM in a different mode or something, and you could tune the service regen tables? No idea....
    2005 Silverado, CC/SB, 4x4, LT, LILLY/Allison
    12.9s @ 108 mph

    many thanks to Ross and Paul

  9. #59
    Senior Member
    Join Date
    Dec 2015
    Posts
    126

    Default

    Quote Originally Posted by DURAtotheMAX View Post

    Believe me, I wish there was a simple scan tool command ($AE) that would make it change modes! Maybe there is, I dont know...maybe you could command a service regen and that would put the ECM in a different mode or something, and you could tune the service regen tables? No idea....
    Tried that. But when you 'disable' the dpf, it also disables the the AE command. Which is interesting. There's alot of other issues with that though. The ECM won't even do it unless the vehicle is stopped anyway.

    I am certain an AE command exists, but Its probably locked behind a dev switch which... All I know is once that switch is disabled it is pretty much impossible to reset it. Not with the equipment I have anyway. Maybe there is a way to edit the tune to make that not happen, but again haven't found anything like that.

  10. #60
    Lifetime Member GMPX's Avatar
    Join Date
    Apr 2003
    Posts
    13,148

    Default

    It is a shame the ECM's OS is as protected as it is (thought it is worse on newer controllers), Ben's concept was very good but would have required each ECM to be opened up and have the modified code (OS) JTAG's in because nobody but Bosch has the signing keys for the OS to be flashed via OBD-II
    I no longer monitor the forum, please either post your question or create a support ticket.

Page 6 of 7 FirstFirst ... 4567 LastLast

Similar Threads

  1. DSP 5 Help
    By BigOlDog in forum Duramax 06 LLY / 06+ LBZ & LMM
    Replies: 4
    Last Post: April 2nd, 2011, 04:36 AM
  2. dsp 5 help
    By mike8890 in forum Duramax LB7
    Replies: 3
    Last Post: March 6th, 2011, 12:39 PM
  3. help with DSP
    By justin123 in forum Duramax 06 LLY / 06+ LBZ & LMM
    Replies: 37
    Last Post: October 22nd, 2009, 12:27 PM
  4. dsp os changes?
    By hot-dog in forum Diesel
    Replies: 1
    Last Post: April 27th, 2009, 09:25 AM
  5. dsp ??
    By tfkostecki in forum Duramax LB7
    Replies: 2
    Last Post: September 10th, 2008, 03:38 PM

Posting Permissions

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