2014 GMC 5.3 Programs now 14 months old problems

[Maverick1]

The very well know and constantly reported issues with the GM 14/15 5.3 ECU and TCM has plagued us for over 14 months now. The lack of support is terrible. The responses if ever received are one liners that produce no results. This series of vehicle is probably one of the highest volumes that use this program, or at least report so. Lets stop the excuses and FIX the problems.

[Betro]

What problems are you having?

[[email protected]]

What problems are you having?

The 1 to 2 shift is rough, at wide open throttle it bangs hard 1 to 2 and 2 to 3. When you're not at wide open throttle it bogs down between 1 to 2 shift like it shifts too soon into 2nd. This has been reported and talked about over and over again with many threads and these guys refuse to do anything about it and I only said that you need to get a custom tune. They also keep saying it's because guys have their trucks customized - completely stock

[Egoresb]

Seems like everyone is having the same issue across the board. Not just Diablo forums but silveradosierra and gmfullsize forums as well.

[Betro]

I haven't had these problems. So far I have this set up....

87 Tune
DOD/AFM off
TCM off
Throttle boost 12%
Shift RPM WOT 1-6 5900
Shift firmness WOT 1-6 8%

All drives fine normally.

[Egoresb]

What year truck? And is it 4x4?

[hockeylove]

My truck is a 2014 Silverado 2wd 5.3 and it has the same issues you guys are having. I had my truck custom tuned and it still has theses issues.

[SmokeShowJoe]

Yep, same here 2014 5.3 4x4, 3.42 87 tune, TCM = firm shift with everything set back to - as far as it will let me, and still SLAMS Really HARD on WFO... I wonder if it's the locker in the G-80 engaging or trying to at such a fast speed... My understanding is they are Not meant to engage at high RPM... Feels like if I had 75 more HP it would lock the G-80 and smoke the rear tires @ 50 mph. So Diablo, time to shi! or get off the pot !! (1) Fix the problem, or (2) Be ready to replace my Tranny and or Rear End on your dime, or (3) I send my tuner back to you and you give me my MONEY BACK. I have a friend who owns a Chevy Dealership here and he has told me that nation wide, Chevy Knows that Diablo turners are BLOWING trannys with the TCM Firm Shift Tune on the trucks at a alarming rate... his words not mine. Diablo keep saying "Their Chevy test truck runs fine with no problems" Tell you what... Fly out here, drive my truck, look me in the eye and tell me it's working just fine... Or better yet, while your here JUST FIX YOUR SOFTWARE...

Has anyone tryed this set up as a fix ??

87 Tune
DOD/AFM off
TCM off
Throttle boost 12%
Shift RPM WOT 1-6 5900
Shift firmness WOT 1-6 8%

[Spiceygoat]

I have a 2015 Silverado with the 5.3 and 6 speed tranny. I have found these settings seem to work the best for my truck

87 octane PCM tune
DOD turned off
10% throttle boost

Stock TCM tune
Torque management turned off

I also have a Corsa sport cat back exhaust installed

I think torque management on these trucks is the culprit. Mine shifted like crap with it turned on, even before tuning it. I'm pretty happy with the configuration.

[Betro]

What year truck? And is it 4x4?

2015 Sierra 5.3l 4x4.

[srice425]

did you guys ever figure out a solution to the trans bogging down when shifting from 1-2 and 3-4?

[Newell33]

Add me to the list of dissatisfied customers. My factory trans tuning was horrible. I purchased the tuner to try to make my 2014 Silverado 6 speed shift like a normal truck. When using the 87 or Diablo Tune, the truck bangs into gear, especially at or near full throttle. I also have the quick 2nd to 3rd shift issue, even with the throttle boost set to 0. The truck also shifts somewhat erratically and inconsistently, just like the factory tune. When the 15304 transfer case recall was implemented, my factory shifting improved dramatically. Now, my 87 and Diablo programs shift considerably worse than the factory tune, especially when using the Tow/Haul mode.

I emailed Diablosport over a month ago and never got a response. I'm very disappointed right now. Is there anyone actually working on improving this tune? I'd really like to use my tuner for something more than shutting off the AFM system.

[mikel]

Add me to the list of dissatisfied customers. My factory trans tuning was horrible. I purchased the tuner to try to make my 2014 Silverado 6 speed shift like a normal truck. When using the 87 or Diablo Tune, the truck bangs into gear, especially at or near full throttle. I also have the quick 2nd to 3rd shift issue, even with the throttle boost set to 0. The truck also shifts somewhat erratically and inconsistently, just like the factory tune. When the 15304 transfer case recall was implemented, my factory shifting improved dramatically. Now, my 87 and Diablo programs shift considerably worse than the factory tune, especially when using the Tow/Haul mode.

I emailed Diablosport over a month ago and never got a response. I'm very disappointed right now. Is there anyone actually working on improving this tune? I'd really like to use my tuner for something more than shutting off the AFM system.

where did you send an email?

Post the backup and last tune written files from the tunes folder here please and I'll check it out.

[Newell33]

Mike,

The email was sent through your "Request Support" link on this site. I've attached what's shown in my tunes folder on the tool. I'm assuming this is the info that you need. If not, please let me know what else I need to provide.

Thanks for the help.

Josh

[mikel]

Mike,

The email was sent through your "Request Support" link on this site. I've attached what's shown in my tunes folder on the tool. I'm assuming this is the info that you need. If not, please let me know what else I need to provide.

Thanks for the help.

Josh

Load this tune and let me know how it feels, do not adjust any throttle boost here.
when tool asks if you want to reset parameters, click yes then load this.