4wd updates to ecm

nadrojcote · October 14, 2015

Maybe everyone who thinks this update made the truck shift better hasn't disconnected their battery in a long time. Doing so resets the learning ability of the tranny and makes it shift better in my opinion. My dealership said it was free even though I'm out of warranty and called it a recall. I do still have power train warranty through.

Newell33 · October 15, 2015

Maybe everyone who thinks this update made the truck shift better hasn't disconnected their battery in a long time. Doing so resets the learning ability of the tranny and makes it shift better in my opinion. My dealership said it was free even though I'm out of warranty and called it a recall. I do still have power train warranty through.

My truck never shifted correctly from day one (about 8 miles on the odometer), and in 19,000 miles it never improved. The update completely changed my truck for the better. I'm very in tune with my vehicles. I'm not sure why you didn't notice a change, but I can assure you that for me this recall was much more than resetting the re-learn procedure.

nadrojcote · October 15, 2015

My truck never shifted correctly from day one (about 8 miles on the odometer), and in 19,000 miles it never improved. The update completely changed my truck for the better. I'm very in tune with my vehicles. I'm not sure why you didn't notice a change, but I can assure you that for me this recall was much more than resetting the re-learn procedure.

I haven't had the recall done yet. I was just referring to the other people that say the recall did nothing to their shifting. Which would make sense because the tcm doesn't get touched with the 15304 recall. I'll update when I have mine done on the 21st. I strongly believe the 1st-2nd and 2nd-1st clunk/clank that lots of people experince is a hardware issue and not a software issue. Mine makes a clank noise with a diabloaport tune as well as stock which makes me think its the clutch pack.

Newell33 · October 15, 2015

I haven't had the recall done yet. I was just referring to the other people that say the recall did nothing to their shifting. Which would make sense because the tcm doesn't get touched with the 15304 recall. I'll update when I have mine done on the 21st. I strongly believe the 1st-2nd and 2nd-1st clunk/clank that lots of people experince is a hardware issue and not a software issue. Mine makes a clank noise with a diabloaport tune as well as stock which makes me think its the clutch pack.

I would guess that you're right, depending on the severity of the clunk. My truck would clunk quite often when downshifting from 6th to 5th, or from 5th to 4th. The downshifts were horrible, and felt like the brakes were applied, and then I'd get the clunk / downshift. That clunk is gone now, which I actually didn't expect. If you have a loud clunk when putting the truck into gear, then I'm guessing the recall won't change anything.

For the record, my truck also acted funny with the i1000. It was slightly better than stock, but it still had plenty of issues. I've tried re-installing (even with stock TCM tuning) and it made the truck worse than the stock tune after the recall. Plus, even without throttle boost, I still had the quick 2nd to 3rd shifting that others have complained about with the Diablo product. My truck is now awesome with the stock tune after the recall, and with AFM turned off with the tuner. I'm not happy with the performance of the Diablo canned tune (also had pinging), so I guess I purchased a $300+ AFM disabler.

gemsierra · October 15, 2015

I had mine updated today. Have not noticed changes in shifting yet. Heres my dealer invoice description

andyhaug · October 15, 2015

Mine was updated at the same time the transmission was replaced. Upshifting is much better now except for the first shift from 2-3 where it slips. Mentioned this at the dealer and they said something about the transmission purging air on the first 2-3 shift. The other thing that I notice now is that when downshifting, it does do a better job finding the right gear, but it also slips a lot. The RPM overshoot about 500 then it slips into gear while accelerating.

Hard to know if this was fixed by the update or the new transmission. At least it isn't trying to kill me anymore. Last transmission would randomly not react to gas pedal movement and try to push me through intersections while braking.

TJay74 · October 15, 2015

This update has nothing to do with shifting at all, I asked the GM engineer about it yesterday and the update only reprograms the transfer case module and nothing else.

Newell33 · October 15, 2015

This update has nothing to do with shifting at all, I asked the GM engineer about it yesterday and the update only reprograms the transfer case module and nothing else.

Read through the thread. There was a post describing how the tccm was handing the torque management software, and how this recall improves driveability due to the updates.

nadrojcote · October 15, 2015

Read through the thread. There was a post describing how the tccm was handing the torque management software, and how this recall improves driveability due to the updates.

torque management for the transmission is handled by the transmission control module. I can't find the post you're talking about but I'm pretty sure I remember it being a speculation not fact.

ZmanII · October 15, 2015

I had the recall done on my truck earlier this week. I don't feel any difference in drive quality. Beside the paperwork saying so, I wouldn't know they reprogrammed anything.

tbarn · October 15, 2015

Did mine, service managers, and service writers. All drive exactly the same.

BIGDOGx · October 15, 2015

Not me, completely fixed my complaints with slow speed shift habits and indecisive gear selecting. Not in my head as I have been driving the truck for a year now and can most definitely feel a major improvement especially at low parking lot type speeds.

Newell33 · October 16, 2015

Did mine, service managers, and service writers. All drive exactly the same.

I still think there were different tunes installed by GM at the factory. This would explain why some owners had horrible shifting that was corrected by the recall, and why some owners said their trucks shifted great right out of the box. I often wondered how those guys could ever call the horrible shifting normal. I'm guessing they were the lucky ones from the beginning, and already had an updated tune of some sort.

TJay74 · October 16, 2015

Read through the thread. There was a post describing how the tccm was handing the torque management software, and how this recall improves driveability due to the updates.

Read thru what I said, I spoke to the head "read" Chief Engineer over the entire GM truck/SUV line about this update, it only reprograms the transfer case module and nothing else, that module is completely separate from the TCM (transmission control module) which handles shifting and the transmission side of torque management.

TJay74 · October 16, 2015

I still think there were different tunes installed by GM at the factory. This would explain why some owners had horrible shifting that was corrected by the recall, and why some owners said their trucks shifted great right out of the box. I often wondered how those guys could ever call the horrible shifting normal. I'm guessing they were the lucky ones from the beginning, and already had an updated tune of some sort.

The calibration are only different based on the engine in the truck, the engine used has different engine tuning and transmission tuning. That is the only difference, otherwise the tunes are the same. You could pull a tune from a 5.3l engine and 6spd auto from the same year and as long as the gears are the same the tune will be the same for both vehicles.