Page 1 of 2 12 LastLast
Results 1 to 20 of 27

Thread: No Throttle Response

  1. #1
    Tuner in Training
    Join Date
    Jun 2017
    Posts
    36

    No Throttle Response

    I have an 06TBSS in my 58 Sedan Delivery. I have a mild cam and long tube headers. I went to a ls3 "card" style MAF and it's never ran that great. I recently decided to go back to the stock MAF and while trying to restore the stock tune I apparently ruined the ECM according to HPT support. So, I have an 05gto for another swap that I pulled the ECM from and the car starts now but has no throttle response. The suite shows the TPS % changing but I don't think that the throttle plate is moving. If I pull the plug on the throttle body the car stalls. I replaced the throttle body and MAF with the gto set up and nothing is changing. If I pull the MAF or MAP plug nothing happens. I've never had the gto running but I'm assuming it did when it hit something hard!
    Please help!
    George

  2. #2
    Advanced Tuner
    Join Date
    Apr 2017
    Location
    Meridian MS
    Posts
    480
    2005 E40 and 2006 E40 have different service numbers. Did you try to put the '06 tune file on the '05 ECM?

  3. #3
    Tuner in Training
    Join Date
    Jun 2017
    Posts
    36
    No but I'll give it a try.
    Thanks!

  4. #4
    Advanced Tuner
    Join Date
    Apr 2017
    Location
    Meridian MS
    Posts
    480
    NO! Don't write a different year. It'll kill it or at minimum cause weird problems - like throttle not working. Which is why I asked if you tried sticking your previous '06 tune on the '05 ECM.

    If you kept the '05 tune file in the '05 ECM, go back and compare '05/'06 pinouts and throttle pedal part numbers to see if there's any differences.

  5. #5
    Tuner in Training
    Join Date
    Jun 2017
    Posts
    36
    Thanks for that heads up. I don't want to mess up the 05 ECM as I need it for another swap. I found an exact match on ebay but the VATS needs deleted which will cost me two HPT credits. I think that's my safest solution. I didn't know that E40's had different pin outs. I thought any E40 could be programmed to match your tune.
    Thanks for your help!

  6. #6
    Advanced Tuner
    Join Date
    Apr 2017
    Location
    Meridian MS
    Posts
    480
    They are different service numbers, but both E40s. Something is different inside between them, internal hardware addresses or something we end-users don't see on this side of the HPT GUI, and the tune files are not compatible. A '05 ECM with a '05 tune on an '06 harness will work just fine, and same for '06/'06/'05, as far as I've seen. But you should always double check pinouts if possible when changing things around like that, just as a safety thing since I don't know anybody has checked all possible combinations. Check it and find nothing different and then you won't have to wonder about it later on if an issue pops up.

  7. #7
    Tuner in Training
    Join Date
    Jun 2017
    Posts
    36
    Thanks Blindsquirrel,
    I never "bastersized" the '06 harness but when I plugged all of the '05 gto stuff I still never got the throttle to work. The only thing I did was delete the VATS. I got another ECM with the exact service code (came from an '06 Impala SS 5.3) and deleted the VATS and I still don't have any throttle response and it idles like crap. If you want, I posted another "help" request in the forum with the tune and scan to look at. The only other thing I've done is change back to the orig MAF which I thing I got it wired right but I'm not sure.

  8. #8
    Advanced Tuner
    Join Date
    Apr 2017
    Location
    Meridian MS
    Posts
    480
    Is the current ECM still running the Impala OS?? 12604792 is not a Trailblazer OS. That's the same OS that was in the Grand Prix E40 I reflashed to use in my Envoy. Don't expect the Impala OS to play nice with the Trailblazer harness, pedal, and throttle body. Also I know there are pinout differences since I did that same swap on mine. Once reflashed the pins are internally reconfigured to match the harness.

    I don't think HPT can write all parts of the ECM even doing a write entire. I know on some of them the throttle section doesn't get written. To do it properly - change from one platform to another - you have to use GM dealer tools to put the base OS files in it.

    I have a running '06 Envoy and the GM tools, if you can't work out something else I can flash and test it if you want to send me a ECM.

  9. #9
    Tuner in Training
    Join Date
    Jun 2017
    Posts
    36
    The service code is 12596679, same as the blazer but when I read it, it said that it came from the Impala. I tried that other one 1204792 but figured out that it wouldn't work.
    Last edited by gpbelton; 07-14-2019 at 02:48 PM.

  10. #10
    Tuner in Training
    Join Date
    Jun 2017
    Posts
    36
    If the service codes are the same, shouldn't the ECM work with a little tweaking?

  11. #11
    Advanced Tuner
    Join Date
    Apr 2017
    Location
    Meridian MS
    Posts
    480
    2006 Impala/Monte Carlo/Grand Prix/Envoy/Trailblazer/Ascender/Rainier/9-7x/SSR/GTO, with 5.3 or 6.0, all use the same Service Number: 12596679. They do not all use the same Operating System. Any 12596679 will work just fine with your Trailblazer harness/pedal/throttle body AFTER is has a Trailblazer-compatible Operating System written to it.

    The Operating System from Impala/Monte Carlo/Grand Prix will not work with the harness, pedal, & throttle body from a Envoy/Trailblazer/Ascender/Rainier/9-7x/SSR, or from a GTO. A GTO Operating System will not work with the harness, pedal, & throttle body from a Impala/Monte Carlo/Grand Prix. The ECM, 12596679, the hardware, is compatible with the Operating System from any of them. The Operating Systems are not compatible across all the different platforms. SSR ECM swapped into a 9-7x uses the same Operating System and, as long as the Calibration (engine size) is the same, it will fire and run as if nothing happened.

  12. #12
    Tuner in Training
    Join Date
    Jun 2017
    Posts
    36
    Where can I find and load a "Trailblazer-compatible Operating System"?
    Thanks again for all this info! I've learned more about tuning in the last few days than I have in two years!
    I was also thinking that repinning the ecm would solve the problem.ss trailblazer tune to copy.hpt
    I have this file but it doesn't tell me what the OS is. It will cost me 2 credits to install it but I'm worried about bricking this computer.
    Last edited by gpbelton; 07-15-2019 at 08:42 AM.

  13. #13
    Tuner in Training
    Join Date
    Jun 2017
    Posts
    36
    I compared the Impala and TBSS wiring schematics and they basically look the same except that the Impala has DOD. I am disabling that to see if that helps.

  14. #14
    Tuner in Training
    Join Date
    Jun 2017
    Posts
    36
    Also realized that the Impala ECM has the 8 pin throttle body plug vs the 6 on the TBSS. Two low ref wires.

  15. #15
    Tuner in Training
    Join Date
    Jun 2017
    Posts
    36
    Disabling DOD didn't change anything.

  16. #16
    Advanced Tuner
    Join Date
    Apr 2017
    Location
    Meridian MS
    Posts
    480
    I have not done a platform change with HPT, I have the GM tools that write all sections of the ECM. I'm not certain about how that works out on an E40, using HPT to do a 'write entire' with a file from the repository. I do know it will cost you credits.

    There are some ECM/PCMs that can't be fully written by HPT. Specifically the throttle controls section. Again, I don't know if the E40 is affected. But the right way to do this is, take your Impala ECM, plug it into a Tech2/MDI, open up TIS2000, feed it a 2WD Trailblazer SS VIN number, and let it eat. Then, once you have a stock GM calibration in it, connect to HPT and license it just the once, and tune away.

  17. #17
    Advanced Tuner
    Join Date
    Dec 2011
    Location
    Amarillo, TX
    Posts
    299
    I agree with blindsquirrel here. I see lots of issues when people start writing entire with various different ECMs and service numbers.
    JTC Performance - Authorized HP Tuners Reseller
    Performance Tuning in the Texas Panhandle

  18. #18
    Advanced Tuner
    Join Date
    Apr 2017
    Location
    Meridian MS
    Posts
    480
    To further beat a dead horse here, there are major pin assignment differences between an Impala file and a Trailblazer file. The ECM hardware is the same, but flashing a different OS changes what certain pins are used for. Some pins are fixed and can't be changed, others are software-configurable. They can be set to be a low ref, a 5v ref, or a signal input, or disabled altogether.

    With the Impala OS, C1 pin 8 is a 5v ref. Trailblazer, it's a low ref. Impala C1 pin 15 'not used', Trailblazer is Class2 Serial. Impala has only one upstream and one downstream O2 sensor, Trailblazer has 2 up/2 down. Impala C1 pin 29 is low ref, Trailblazer is 5v ref. C1 pin 52 Impala is 'not used', Trailblazer is crank voltage. And so on down the list.

    The way you change those pin assignments to match your harness and the components the harness goes to is to flash the ECM with a compatible Operating System.

  19. #19
    Tuner in Training
    Join Date
    Jun 2017
    Posts
    36
    Where can I find someone with the Tech2/MDI hardware and the knowledge to rewrite the ECM? Will this also correct the pin assignments?

  20. #20
    Advanced Tuner
    Join Date
    Apr 2017
    Location
    Meridian MS
    Posts
    480
    Yes, changing from an Impala to Trailblazer OS will switch the pin assignment from Impala to Trailblazer.

    Whereabouts in this big wide world are you located? If you can't find someone local you can send it to me, I can plug it into my truck and program it to GM's latest calibration for whatever VIN number you need.