Allison 6sp: Important 2015.5+ Allison info

[duratothemax]

I figured I would start a new thread devoted to the new 2015.5+ Allison TCM just to give everyone a heads up on the details.

Mid-year 2015, roughly after August 2014 build date, GM/Allison made some changes to the transmission wiring harness, changed to a new TCM, and new speed sensors.

The speed sensors changed from the traditional AC 'analog' variable-reluctance type (IE, the type that has been around for 30 years) to newer DC hall-effect sensors that produce digital (square wave) signals. DC/hall-effect sensors are more accurate, less susceptible to signal noise/interference.

And from an electrical/technical standpoint, its also possible with DC sensors for the TCM's to run more advanced diagnostics on the circuit and sensor...which gives more precise information to the scan tool when there is a fault, thus making it easier for technicians to diagnose problems. Yaddyaaddyaydaaa blah blah blah....

If you have a 2015 truck, look at your glovebox RPO sticker... if you see the code "AVF", that means your truck is a late-build 2015, and has the new DC speed sensors and new TCM.

The TCM on 2015.5+ trucks with "AVF" RPO code is completely different. The 2015.5/AVF trucks no longer use an Allison A40/A50/T14 controller. They now use the GM T87 controller. It looks completely different, has a different connector, and is made by Hitachi. Its the same TCM that the 8-speed 8L90 in the new Corvette and 6.2 half ton Silverados has.

So now the Corvette (w/ 8-speed auto), 2015+ half ton silverado (w/ 8-speed auto), and 2015.5+ Silverado HD (w/ Allison and AVF code) all share the same new T87 controller.

And no, you cant swap to the older 2006-2015 Allison A40/A50/T14 TCM because the connector on the 2015.5+ T87 is completely different and the digital speed sensors are incompatible with the older A40/A50/T14 TCM.

Ben

 

[DAVe3283]

Actually, I wonder if this won't end up being a good thing? It seems that EFILive has always supported the GM transmission computers / operating systems far better than they did with the Allison.

 

[WolfLMM]

Actually, I wonder if this won't end up being a good thing? It seems that EFILive has always supported the GM transmission computers / operating systems far better than they did with the Allison.

My thinking as well.

 

[Mike L.]

I will be ordering one next week.

 

[WolfLMM]

Wonder how the shifting will be? I ASSume the new tcm will be running GMs algorithms and no longer using allisons.

Not to nitpick, but the 6L series transmissions don't shift anywhere near the smoothness of the ally. Not sure on the 8L as I have never rode in one.

 

[jkholder09]

This makes me wonder if the tfp switch manifold has been deleted as in most other modules, and the tcm is diagnosing clutch slip or shift valve train issues using calculated gear ration now. The other gm transmission with a digital speed sensor have went to that strategy.
It makes diagnostics a bit harder because you can no longer see the button being pressed when a valve is stroked in the bore.
It does save gm about 150$ per unit though.

 

[NC-smokinlmm]

I have a few buddies with 15.5's they are all complaining about vibration in the drivetrain. Anybody else heard anything about this, did GM change anything else bc mine is smooth as silk and it's a early 15...

 

[Mike L.]

I have a few buddies with 15.5's they are all complaining about vibration in the drivetrain. Anybody else heard anything about this, did GM change anything else bc mine is smooth as silk and it's a early 15...

I have done 5 15.5 Allison and have not experienced any vibration. Wonder if your buddies aren't mistaking the vibration with the lane sensor feedback?

 

[56taskforce]

I have done 5 15.5 Allison and have not experienced any vibration. Wonder if your buddies aren't mistaking the vibration with the lane sensor feedback?

TURTLES???? Mike sometimes it is hard to tell if you are being technical or funny. I guess that comes with the wolf in sheep's clothing thing :mikelsheep:

 

[Mike L.]

TURTLES???? Mike sometimes it is hard to tell if you are being technical or funny. I guess that comes with the wolf in sheep's clothing thing :mikelsheep:

I'm being serious here. Go drive one and see what happens when you get too close to the yellow line.

 

[DIESELMAFIAPER.LB7]

Seriously they have lane sensors? that's annoying as shit can they be shut off?

 

[Mike L.]

Seriously they have lane sensors? that's annoying as shit can they be shut off?

If you get too close to the right side yellow line; the right side of the seat vibrates and vice versa. First time I drove one I thought I was sitting on my cell phone.

 

[duratothemax]

Seriously they have lane sensors? that's annoying as shit can they be shut off?

UGH yes of course you can turn it off. RELAX.

Dont be too quick to judge and shit on this technology. Next time you doze off on a long drive, it just might make it so you get to your destination in one piece. More than once ive been snapped awake because I closed my eyes for 2 seconds and hit the rumble strip. Not all highways have rumble strips though.................

Oh and the dumb soccer mom in her Suburban who is trying to feed apple sauce to the kids in the back while driving, and accidentally drifts into your lane as you're overtaking her hauling a 30' trailer...oh wow gee whiz, another accident avoided, thanks lane-departure warning.

Would you want to fly on an airliner that doesnt have TCAS or GPWS?

And as a side benefit, lane-departure warning will actually force idiots to start using their blinkers too...because it will chime at them if you change lanes without signaling.

In 20 years all you stubborn old farts are going to look back on this and say "wow...why didnt we think of this sooner?". :

Volvo made a public statement back in 2010 that by the year 2020, no one would be killed in a new Volvo. Lane-departure warning is one of the many "dumb technologies" that will allow them to reach that goal.

Ben

 

[Robby05]

Oh and the dumb soccer mom in her Suburban who is trying to feed apple sauce to the kids in the back while driving

Ben

:roflmao:

 

[DIESELMAFIAPER.LB7]

So rather then teach people to drive and pay ****in attention to the road we build the cars to do it for us an make us lazy...... this is where I disagree with you on a lot of things Ben some technology is nice to incorporate yes. But if I don't want to use my blinker when I'm the only one on the road I don't want to get any shit from my truck about it. Also I don't drive when I'm so tired I doze off I regularly drive 12+ hours though and I will say I do ride the white line at times guess our wife's will like this new technology 60k dildos:rofl:

Also airplane comparison isn't a good one we fly our Mooney with just vor and adf so lol oh and a compass ha ha not a airline but they used to do it that to and did just fine

 

[DIESELMAFIAPER.LB7]

If you get too close to the right side yellow line; the right side of the seat vibrates and vice versa. First time I drove one I thought I was sitting on my cell phone.

Lol don't lie mike you were just sitting enjoying the vibration :rofl:

 

[OregonDMAX]

So rather then teach people to drive and pay ****in attention to the road we build the cars to do it for us an make us lazy...... this is where I disagree with you on a lot of things Ben some technology is nice to incorporate yes. But if I don't want to use my blinker when I'm the only one on the road I don't want to get any shit from my truck about it. Also I don't drive when I'm so tired I doze off I regularly drive 12+ hours though and I will say I do ride the white line at times guess our wife's will like this new technology 60k dildos:rofl:

Also airplane comparison isn't a good one we fly our Mooney with just vor and adf so lol oh and a compass ha ha not a airline but they used to do it that to and did just fine

I agree partly, its like how backup cameras make it to now these shitty drivers dont ever uses their mirrors anymore.

 

[DIESELMAFIAPER.LB7]

I agree partly, its like how backup cameras make it to now these shitty drivers dont ever uses their mirrors anymore.

Exactly my point. Not saying all of it is bad but some of the stuff is borderline retarded. Anyway sorry I won't muck up and detail this anymore. I can't wait to see how the new tcm plays into things

 

[duratothemax]

So rather then teach people to drive and pay ****in attention to the road we build the cars to do it for us an make us lazy......

Well ya know what, the reality of the situation is that there are always going to be bad drivers out there. I agree with this sentiment ("we shouldnt need to rely on technology, we should just be better drivers"), but I also disagree with it...heres why. No one is a perfect driver (or at least as good as you), so we gotta work with what we have. If a piece of technology can stop someone from veering into my lane and causing an accident, whether or not the driver in question sucks, fell asleep, or whatever...IDGAF. The reality of the situation is, the technology averted the accident. Thats what matters.

Is it dumb that we need to rely on technology to keep the bad drivers safe? Yeah sure, I guess, but again, some people just suck....and theres no changing that. Its not like we can screen out the shitty drivers and say "ok...you're fine...you're fine...no, you're not fine, hand over your license", so the best we can do is give the idiots a helmet and electronic training wheels...so be it. If thats what it takes to lower accident rates, than who cares!

Also airplane comparison isn't a good one we fly our Mooney with just vor and adf so lol oh and a compass ha ha not a airline but they used to do it that to and did just fine

Yes good luck with using your ADF and VOR (those exist still? I thought VOR stations were just funny dunce-cap looking things that the FAA left standing for aerial visual comic-relief, surely no one actually uses them anymore?) for any real navigating on January 1st 2020. Since you're a pilot you know what I mean by that.

And do you have any idea what the statistics are of CFIT accidents before the mid-70's (when GPWS was mandated on part-121 aircraft) and after the mid-70's? CFIT accidents dropped from a surprisingly-scarily-common occurrence to basically NONE after ground-prox was mandated.

TONSSSS of 20,000+ hour ATP-rated pilots have flown perfectly good-working non-GPWS-equipped airplanes right into the ground. And thats with TWO pilots checking eachothers work!! They still managed to do it! People make mistakes, people are dumb. :rofl:

Ben

 

[TheBac]

More traffic on the roads, less attention to teaching basic defensive driving strategies in the first place, far more distractions while driving and newer cars having to be made safer with lighter materials is really what's driving these extra safety options.

Just wait til cars begin to drive themselves. Its coming, probably in my lifetime. (unless I die in the next couple years)


Ben, calm down. Some of us would rather depend on our skills instead of needing a machine to do it for us. Nothing wrong with either decision.