Tuners For 2018 Sierra "Hybrid" Truck?

beerpilot · March 14, 2019

I got a 2018 GMC Sierra with the eassist package. I never thought of this thing as a hybrid but GMC does classify it as such. One of the digits in the VIN specifies that distinction.

I also recently picked up a Hypertech Max Energy 2 because I liked the options it provides for the AFM, specifically the speed at which it operates.

The Hypertech didn't work, says the truck is not supported. A call to their tech support confirmed that the issue was the fact that the truck is a hybrid and they do not support that.

So my question for the forum is, anyone know of a tuner that is supported on this "hybrid" pickup?

From reading sites of other tuners it doesn't look like anyone makes this distinction of hybrid. I can return the Hypertech so a trial & error approach of purchasing another tuner and seeing if it would work is possible, but time consuming and annoying.

Thanks in advance for help or suggestions.

KARNUT · March 14, 2019

I got a 2018 GMC Sierra with the eassist package. I never thought of this thing as a hybrid but GMC does classify it as such. One of the digits in the VIN specifies that distinction.

I also recently picked up a Hypertech Max Energy 2 because I liked the options it provides for the AFM, specifically the speed at which it operates.

The Hypertech didn't work, says the truck is not supported. A call to their tech support confirmed that the issue was the fact that the truck is a hybrid and they do not support that.

So my question for the forum is, anyone know of a tuner that is supported on this "hybrid" pickup?

From reading sites of other tuners it doesn't look like anyone makes this distinction of hybrid. I can return the Hypertech so a trial & error approach of purchasing another tuner and seeing if it would work is possible, but time consuming and annoying.

Thanks in advance for help or suggestions.

Just go to their website for the info.

Sent from my iPhone using Tapatalk

beerpilot · March 14, 2019

Guess I wasn't clear when I mentioned that I had read sites. The vendors websites do not make a distinction between a regular 2018 GMC Sierra and the hybrid model. There is no way (that I have been able to discover) to figure this out using published data.

A call to the manufacturers tech support is probably the way to go, or trial and error. Maybe Hypertech is the only one to make the distinction for all I know.

I'm guessing my question will go nowhere but perhaps my post will serve as a heads up for others with this type of vehicle.

beerpilot · March 14, 2019

Update. I called Diablosport to ask about their predator line. They do not support the hybrid models either, in fact said they didn't think anyone was yet as there isn't enough demand yet. They also said their engineers are not working on a solution as yet.

Also referred to the engine as a hybrid engine, they guy on the phone made that distinction. Seems odd that the actual engine would be different, all it has is a electric motor bred into the drivetrain, but maybe it is somehow different than the regular 5.3L gas engine, who knows.

Sgonza101 · March 14, 2019

I used to have a 2005 Silverado hybrid, nobody made a tune for it. I looked at custom tunes and most shops said no. Some said they could try it but it would be pricey. Does your truck have an alternator? My 2005 did not, it had a stator but it was placed in the transmission. My recommendation is to stay away from hybrids I had to junk my truck due to Chevrolet not making that part anymore.

Yondu · March 15, 2019

If there is any possibility of a tune I'd think you would want to contact HpTuners.

Mike GMC · March 15, 2019

Have you talked to Black Bear?

3tspapat · March 15, 2019

I contacted black bear late last year. They said they could tune the engine just not the transmission.

People also said no CAI for the eAssist. Well I made one fit. It’s jist a demand thing. Why put time and effort into something that won’t make you any money? Oh simply because you love tuning and enjoy a challenge! That would be the tuner to go to.

This forum needs an eAssist forum. Did you know that eAssist also helps to keep the motor in V4 longer than non-hybrid models?

beerpilot · March 15, 2019

Thanks for the responses. I just looked at Black Bear, wow they are a little pricey. The HP looks a lot more complex than I feel like dealing with, it's pricey also. I was looking for a simpler solution, the Hypertech also supported the one thing that annoys me the most, the way the truck stays iv V4 mode too long and too early. I don't mind V4 on the highway but in town, it's annoying. Hypertech allows a set point for AFM to operate.

I did a bit more research on eassist and it's like I thought, the truck appears to be the same as all the other trucks without eassist. Except for the small induction motor bred into the drivetrain and the Lithium Ion battery pack. Couple other minor items also but the engine appears to be the same as all the others.

I'm guessing the transmission issue with Black Bear is because the truck uses the 8 speed and they haven't figured out what to do with that yet.

The guy who mentioned the alternator issue, without taking the air intake off I can see enough of the front of the engine to say if it has one or not. There appeared to be enough things on the belt system for an alternator but they were hard to see, I'm guessing if all the other 2018 5.3L Sierras have an alternator then this one does also.

I'm going to sit on this for awhile, if enough of these eassist things sell someone will start making tuners for them.

I also agree that a separate forum for eassit would be nice.

3tspapat · March 15, 2019

Drive in L7. That will shut off V4/AFM and also start stop feature. I do this consistently and only set to “D” if I’ll be on the highway for prolonged trips. Even short trips I leave in L7. At 70 mph rpm is around 2200 so not bad at all.

The way I see it, if it came from a factory with a stock tune, then it can be tuned. It’s just a matter of who wants to take the time to learn to tune it.

Oh get a catch can.

Edited March 15, 2019 by 3tspapat

beerpilot · March 15, 2019

Already have catch can on my list of things to do. Just got back from getting a Magnaflow cat back installed, sounds way better. Never thought of experimenting with the manual transmission selections, I will definitely do that. Thanks for that particular hint, can't wait to get on the road and try it out.

3tspapat · March 21, 2019

With the new pipes you will be able to tell when it goes in and out of V4. L7 is the simple fix. But for a long term, I'm still waiting for Range to get their support for 5.3L with V8. So far they are only able to disable auto stop feature but not AFM. Running their device now would be the same thing as driving in D8 where you get all gears + AFM but no start/stop.

Really need that overdrive gear. I think doing that would probably yield better mileage on my commute than in D7 or driving in D with everything on.

Keep on searching for tuners. I will do the same. I really hate that initial lag/hesitation that happens when I'm starting from stop at light throttle.

MODS....can we please get a sticky for eAssist vehicles? like an official eAssist thread?

Edited March 21, 2019 by 3tspapat
Add message for Mods

Nitrousbird · March 21, 2019

HP Tuners is the way to go. Also the only option for tunning the TCM on a '18. It isn't THAT complicated, price isn't bad for what you get and you can always buy a used tuner and credits to tune your truck.

It is the right way to do it. Hand helds are kind of a joke IMO.

IncisionInd · April 4, 2019

Hey Everyone,

Just wanted to Bump this thread and see if anyone has had any luck finding a tuner. Looking to just get a little more performance out of my EAssist.

@3tspapat Which CAI did you make fit if you don't mind me asking? Would love to look at getting one put on the truck.

3tspapat · April 4, 2019

Justin at Black Bear said they should be able to tune it. I'm not sure if they have done any at all though. That is the only confirmation that I have based on the other tuners that I've reached out to. Those who have said it's IMPOSSIBLE...well...it's not. Just too much effort for you.

The conclusion that I have come to is that it's the dollar in returns is less than the dollars in R&D for any eAssist vehicle so aftermarket places aren't doing much of anything for supporting mods. Just need to find someone who would do it out of pure love to tune things and not just to make a buck. Sort of like how some were able to find ways of tuning electric vehicles and other hybrids.

@IncisionInd I got the GMPP CAI to work. Just had to do some cutting and then a 90 degree reducing elbow. Just getting that elbow to clear the coolant overflow (or just extending lines and mounting the overflow to the open area where the old battery used to be), you would be able to get any CAI to work.

I'm on the fence on buying a monitor to see what the the difference this thing has on performance. Just general stuff like timing, knock, etc. at WOT and while putting around. eAssists are a bit weird. ECU is programmed to keep the vehicle in lower gear and use the e-motor when accelerating in same gear and also use e-motor to keep the vehicle in V4 longer. Gotta tune that crap out, drive in L7, or drive in L7 and tow mode.