Strange tranny behavior (I think).

[5280tunage]

Interesting, thanks for the explanations. I will give this a shot on the long drive home, with that said, I'll be curious what the bet effect is since this trip (and most of mine for that matter) include several mountain passes of 8k plus feet.

I'd like to limit the thuds if possible, rather not destroy anything.

 

[AKentPhoto]

So it sounds like a trans tune issue... Might be worth mentioning to the service manager. I'd tell them you can trigger rear end collision level shifts pretty much on the fly and show them.

Anybody with a trans tune want to try this and see if they were able to fix the issue?

 

[Mike K]

Yesterday at 5:07 AM#20

New
Dice Roll hit it on the head. The Lockup is VERY sensitive in these 10 Speeds. Basically it changes gear with out an unlock under some conditions. I have logged it. And it causes that jolt, because it is a hard connection and not through fluid.

Cruise Control is actually not affected itself by Modes, throttle mapping is. Cruise control uses the same throttle mapping of the active mode, just for clarity. End result, is why like wakeboarder I prefer Eco when using Cruise, throttle input is smoother.




Thanks for the tips. I have a 2019 max xlt and I use my cruise control a lot,living here on the big island. Should I be keeping the mode on eco when in cruise control?

 

[theoldwizard1]

As for the cross winds, when you need tires make sure to buy Light Truck (LT) tires. They have stiffer sidewalls and will not react as much to crosswinds. They will require a higher tire pressure and will ride a bit harsher.

 

[Teasip]

Frankly I don't trust ACC. Too many complaints of rapid breaking, rapid acceleration. Maybe the clunking is because the ACC does not behave a like a normal person would drive? FYI, glad I don't have or use ACC on my 2018 Expedition Max. When I am in cruise control on the Interstate driving I stay alert and anticipate situations ahead etc., feathering the throttle up and down via steering wheel buttons. When passing I feather up usually staying in gear 10, I have gotten 25 mph on 1000 mile trips via Interstates.

 

[5280tunage]

As for the cross winds, when you need tires make sure to buy Light Truck (LT) tires. They have stiffer sidewalls and will not react as much to crosswinds. They will require a higher tire pressure and will ride a bit harsher.

Thanks for the advice. Now on to the fun stuff, so on the way back (another 6 hour or so drive), i had some more fun.

About a third of the way back, with the vehicle on ACC and using Eco mode, I had CEL. Basically, I had deactivated ACC by using the brake while coming down a pass. immediately after hitting the brake to slow down, I got the CEL.

Once I got home, I hooked up forscan to review the DTC's and found a plethora of these puppies, now to be fair, some of these I've had quite a few times, almost every time I hook up forscan. And at least one of them I'm guessing was due to updating Sync to 3.4 a couple weeks ago.
DTC's:
P130D:00-68 - looked this up, looks like just about anything can cause this. Anyone experience this one due to a CAI? I have the proper breathing tube piece that is supposed to help stop this (came with the CAI), that's all i can think of.
U0184:00-08, U024B:00-08, U024C:00-08 - looked these up, I've seen these almost every time I hook up my forscan. Looks to be network issues with the seat control modules. Assuming this is kind of normal in these?
U0140:00-08 - looked this up and I can't find much info on it, i didn't see any bulletins that matched the 2019 Expy related to this, thoughts?
B1471:13-08 - again i think this is related to the seat control module losing connectivity.

Update 2 to this thread:
Just went on two separate about 1.5hr drives today, and both times, this thing had roughly the same DTC's. And I just realized this means that my four hour drive yesterday, and 3 hours today were both running in reduce power mode. Not happy.
So on both of these short runs, the DTC happened as I was slowly accelerating on the highway, running around 75mph in 10th gear. Both times this happened, the vehicle was shifting from 10th to 9th under light acceleration on the highway, starting around 70mph, and at around 2k RPM.
This time, the two codes were P130D:00-6C.

Any thoughts? I don't think this is intake related at all, given that this has never happened to me, until that massive clunk for which this post is about, and I haven't modified anything on this recently. This seems transmission related.

Appreciate the help, I've only put 5K miles on this thing, I'm not going to be happy if this thing has tranny issues already.

This is fun!

 

[5280tunage]

Frankly I don't trust ACC. Too many complaints of rapid breaking, rapid acceleration. Maybe the clunking is because the ACC does not behave a like a normal person would drive? FYI, glad I don't have or use ACC on my 2018 Expedition Max. When I am in cruise control on the Interstate driving I stay alert and anticipate situations ahead etc., feathering the throttle up and down via steering wheel buttons. When passing I feather up usually staying in gear 10, I have gotten 25 mph on 1000 mile trips via Interstates.

I get it, I too prefer to be in control but ACC is nice. I had it on my 2011 WK2 and it worked flawlessly. Of course that system was based on LiDar so we'll see how this one goes. I believe this one is just a combination of radar and camera correct (assuming because there is no LiDar pod on the front of this that I've found yet). Regardless, It works great, and I averaged about 21mpg but that's up and down several thousand feet of elevation over about 3 small to large mountain passes, and some 30-40mph winds. I consider that pretty good.

 

[Jay Dubs]

Dice Roll hit it on the head. The Lockup is VERY sensitive in these 10 Speeds. Basically it changes gear with out an unlock under some conditions. I have logged it. And it causes that jolt, because it is a hard connection and not through fluid.

Cruise Control is actually not affected itself by Modes, throttle mapping is. Cruise control uses the same throttle mapping of the active mode, just for clarity. End result, is why like wakeboarder I prefer Eco when using Cruise, throttle input is smoother.

Does a code get thrown or is there some way for the dealer to see the lockup issue without being able to reproduce?

 

[LokiWolf]

Does a code get thrown or is there some way for the dealer to see the lockup issue without being able to reproduce?

I have not seen it throw a code, but didn't look specifically for it. I am not sure it is an "issue". It might be expected behavior. If it is an issue for you, I recommend getting it on the books with your Service Writer, so that if it gets worse after warranty is out, it might be covered as a preexisting issue.

I tend to squeeze the throttle vs punch from driving diesels for so many years. I have only felt the issue maybe 2 times. I have seen it happen when logging but didn't feel it. So I think under lighter throttle inputs it is a non-issue.

 

[5280tunage]

I have not seen it throw a code, but didn't look specifically for it. I am not sure it is an "issue". It might be expected behavior. If it is an issue for you, I recommend getting it on the books with your Service Writer, so that if it gets worse after warranty is out, it might be covered as a preexisting issue.

I tend to squeeze the throttle vs punch from driving diesels for so many years. I have only felt the issue maybe 2 times. I have seen it happen when logging but didn't feel it. So I think under lighter throttle inputs it is a non-issue.

Hey LokiWolf, did you happen to see this update (curious if these codes in anyway could be happening because of the massive clunk, never had them before that event):


Thanks for the advice. Now on to the fun stuff, so on the way back (another 6 hour or so drive), i had some more fun.

About a third of the way back, with the vehicle on ACC and using Eco mode, I had CEL. Basically, I had deactivated ACC by using the brake while coming down a pass. immediately after hitting the brake to slow down, I got the CEL.

Once I got home, I hooked up forscan to review the DTC's and found a plethora of these puppies, now to be fair, some of these I've had quite a few times, almost every time I hook up forscan. And at least one of them I'm guessing was due to updating Sync to 3.4 a couple weeks ago.
DTC's:
P130D:00-68 - looked this up, looks like just about anything can cause this. Anyone experience this one due to a CAI? I have the proper breathing tube piece that is supposed to help stop this (came with the CAI), that's all i can think of.
U0184:00-08, U024B:00-08, U024C:00-08 - looked these up, I've seen these almost every time I hook up my forscan. Looks to be network issues with the seat control modules. Assuming this is kind of normal in these?
U0140:00-08 - looked this up and I can't find much info on it, i didn't see any bulletins that matched the 2019 Expy related to this, thoughts?
B1471:13-08 - again i think this is related to the seat control module losing connectivity.

Update 2 to this thread:
Just went on two separate about 1.5hr drives today, and both times, this thing had roughly the same DTC's. And I just realized this means that my four hour drive yesterday, and 3 hours today were both running in reduce power mode. Not happy.
So on both of these short runs, the DTC happened as I was slowly accelerating on the highway, running around 75mph in 10th gear. Both times this happened, the vehicle was shifting from 10th to 9th under light acceleration on the highway, starting around 70mph, and at around 2k RPM.
This time, the two codes were P130D:00-6C.

Any thoughts? I don't think this is intake related at all, given that this has never happened to me, until that massive clunk for which this post is about, and I haven't modified anything on this recently. This seems transmission related.

Appreciate the help, I've only put 5K miles on this thing, I'm not going to be happy if this thing has tranny issues already.

This is fun!

 

[LokiWolf]

Hey LokiWolf, did you happen to see this update (curious if these codes in anyway could be happening because of the massive clunk, never had them before that event):


Thanks for the advice. Now on to the fun stuff, so on the way back (another 6 hour or so drive), i had some more fun.

About a third of the way back, with the vehicle on ACC and using Eco mode, I had CEL. Basically, I had deactivated ACC by using the brake while coming down a pass. immediately after hitting the brake to slow down, I got the CEL.

Once I got home, I hooked up forscan to review the DTC's and found a plethora of these puppies, now to be fair, some of these I've had quite a few times, almost every time I hook up forscan. And at least one of them I'm guessing was due to updating Sync to 3.4 a couple weeks ago.
DTC's:
P130D:00-68 - looked this up, looks like just about anything can cause this. Anyone experience this one due to a CAI? I have the proper breathing tube piece that is supposed to help stop this (came with the CAI), that's all i can think of.
U0184:00-08, U024B:00-08, U024C:00-08 - looked these up, I've seen these almost every time I hook up my forscan. Looks to be network issues with the seat control modules. Assuming this is kind of normal in these?
U0140:00-08 - looked this up and I can't find much info on it, i didn't see any bulletins that matched the 2019 Expy related to this, thoughts?
B1471:13-08 - again i think this is related to the seat control module losing connectivity.

Update 2 to this thread:
Just went on two separate about 1.5hr drives today, and both times, this thing had roughly the same DTC's. And I just realized this means that my four hour drive yesterday, and 3 hours today were both running in reduce power mode. Not happy.
So on both of these short runs, the DTC happened as I was slowly accelerating on the highway, running around 75mph in 10th gear. Both times this happened, the vehicle was shifting from 10th to 9th under light acceleration on the highway, starting around 70mph, and at around 2k RPM.
This time, the two codes were P130D:00-6C.

Any thoughts? I don't think this is intake related at all, given that this has never happened to me, until that massive clunk for which this post is about, and I haven't modified anything on this recently. This seems transmission related.

Appreciate the help, I've only put 5K miles on this thing, I'm not going to be happy if this thing has tranny issues already.

This is fun!

Yeah, I will dig in to the codes. Some are "normal", as long as they don't cause the CEL. I will get back to you.

 

[5280tunage]

Yeah, I don't really care about the seat control modules or the network issues, just the P130D as that is causing the reduced power state. It's definitely a Knock sensor issue. Some talk about Gas, but I've run almost four tanks through this in the last two weeks, and in CO I can only get 91 octane, so for the super long drives, I added Lucas octane boost (some argue this doesn't really help at all) but I've never had issues with it in this vehicle or previous ones. 3 out of those 4 tanks were from the GM owned "Top Tier" stations. I don't think it's fuel quality.

Especially since it's not happening at all in city driving, it's only happening so far when accelerating at highway speeds, so far every time when the vehicle slowly shifts from 10th to 9th. I tried about half a dozen times yesterday to get it to happen in city driving but it would never go all the way to 10th, so I was testing from 9th to 8th. No dice.

So far, I've checked the following:
- hose clamps related to air intake - good
- oil level - a tad high, drained some - but doubt this was the issue as it just now started
- will check hoses on intercooler today, just to make sure they are tight - checked, everything nice and snug and tight

 

[Dice Roll]

Busy and haven’t read your posts closely. The gist I get is the tranny doesn’t like high load situation of highway speeds in highest gear. Ominous.

 

[5280tunage]

That's what it feels like. Spent about another hour on the highway yesterday and no issues. So it feels quite random. I'm sure at this point, I'm going to have to take it in, which kills me with such a new rig, and there's no decent dealer close, so I have to drive a ways away, and sit in a lobby while they diag it for hours. Fun fun.

With that said, has anyone seen this guide? https://static.oemdtc.com/GSB/G0000128.pdf. Scares the crap out of me, it's basically a cheat sheet for techs, if you see this, you can blame it regardless of whether it's really the issue.

Literally, this article tells the tech to look for things like an air intake for this DTC. So if its tranny related, they may just blame my intake. Should be fun.

 

[rjdelp7]

At those speeds, you may of engaged the rev limiter. Making a pass at 82mph, right? Your engine most likely was near the red line. The PCM pulled power as it shifted. The new transmissions try to rev match, for each gear. Have the dealer update the software for the powertrain. Tell them you had some hard shifts.

 

[Dice Roll]

That's what it feels like. Spent about another hour on the highway yesterday and no issues. So it feels quite random. I'm sure at this point, I'm going to have to take it in, which kills me with such a new rig, and there's no decent dealer close, so I have to drive a ways away, and sit in a lobby while they diag it for hours. Fun fun.

With that said, has anyone seen this guide? https://static.oemdtc.com/GSB/G0000128.pdf. Scares the crap out of me, it's basically a cheat sheet for techs, if you see this, you can blame it regardless of whether it's really the issue.

Literally, this article tells the tech to look for things like an air intake for this DTC. So if its tranny related, they may just blame my intake. Should be fun.

id pull that intake then just so it won’t get the blame. Especially with a drive involved.

 

[5280tunage]

At those speeds, you may of engaged the rev limiter. Making a pass at 82mph, right? Your engine most likely was near the red line. The PCM pulled power as it shifted. The new transmissions try to rev match, for each gear. Have the dealer update the software for the powertrain. Tell them you had some hard shifts.

I would love to agree with you but that wouldn't really explain the additional two CEL's during normal driving, say merging on to a highway at moderate power.

 

[5280tunage]

id pull that intake then just so it won’t get the blame. Especially with a drive involved.

Ugh, they are a bit of a pain in the rump to wiggle in and out. But yeah, might have to.