What did you do to your NNBS GMT900 Tahoe/Yukon Today?

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Ivanhoe

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What's your engine hours. We are doing a study.


Just over 5000hrs with 290000kms (180000 ish miles)
 

Doubeleive

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My new transmission is in. The mechanic confirmed the old one was cooked. I had him change all the diff and transfer case fluids while he had it, and flush the cooling system since it got a new radiator.

Now he tells me I have to take it to the local GM dealer to re-flash the ECM so it'll recognize the new TCM. He says it drives fine, but is throwing a bunch of codes because it thinks it doesn't have a transmission.

This will erase my BB tune. And I'll have to pay a local shop to re-disable AFM (I refuse to deal with BB since they reneged on their lifetime tunes promise). This assumes, of course, that the dealer doesn't do something stupid like refuse to touch it because it's tuned. I'll try playing dumb and say I bought it like that. But the way my luck has been going lately, I won't be surprised if I get caught in no-man's land with the transmission shop and the dealer blaming each other for a bricked ECU, or worse. Wish me luck, lol.
I would not even utter the word tune, just say it needs the tcm learned
 

the_tool_man

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That was a fun 3 mile drive from the transmission shop to the GM dealer. The instrument panel looked like a Christmas tree. Lots of warning messages; stabilitrack, traction control, blind spot sensors, ABS, etc. No gear indicator display. No backup camera. It wouldn't pull from a stop without full throttle. And it wouldn't shift out of 2nd gear. It's crazy how dependent this thing is on electronic communication.

I opted for the airbag recall. Why not.
 
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Just Fishing

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My new transmission is in. The mechanic confirmed the old one was cooked. I had him change all the diff and transfer case fluids while he had it, and flush the cooling system since it got a new radiator.

Now he tells me I have to take it to the local GM dealer to re-flash the ECM so it'll recognize the new TCM. He says it drives fine, but is throwing a bunch of codes because it thinks it doesn't have a transmission.

This will erase my BB tune. And I'll have to pay a local shop to re-disable AFM (I refuse to deal with BB since they reneged on their lifetime tunes promise). This assumes, of course, that the dealer doesn't do something stupid like refuse to touch it because it's tuned. I'll try playing dumb and say I bought it like that. But the way my luck has been going lately, I won't be surprised if I get caught in no-man's land with the transmission shop and the dealer blaming each other for a bricked ECU, or worse. Wish me luck, lol.

Know someone with hptuners?
If you do, pull the tune first!

I also heard that hp tuners might be able to flash the transmission tune vs having the dealership do it.
either way, get a backup of that tune.

Bad part, if the tcm is already removed.
then I believe you lose the bb tune for the transmission?

If you wanted to back it up, this will do the task.
Has two credits.
You will need one for the ECM, and one for the TCM.

You can also buy this w/o any credits and save $100.
 

the_tool_man

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Know someone with hptuners?
If you do, pull the tune first!

I also heard that hp tuners might be able to flash the transmission tune vs having the dealership do it.
either way, get a backup of that tune.

Bad part, if the tcm is already removed.
then I believe you lose the bb tune for the transmission?

If you wanted to back it up, this will do the task.
Has two credits.
You will need one for the ECM, and one for the TCM.

You can also buy this w/o any credits and save $100.
The transmission shop I used, really more of a custom tuning place, uses HPTuners. He said he couldn't retune it if an AutoCal had already done it. He was afraid it would brick the ECM. He said he would re-do the tune (disable AFM, rear O2s) after the dealer is done re-flashing. It'll cost me about the same as BB would charge to do it (again).
 

Geoffsfas10

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Filled it with dinosaur juice....and turns out my passanger side HID bulb is on its way out, its purple now! SO new ones on order
 

Tonyv__

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Looking for a favor from anyone who lives life on the edge with no TPMS.

I’m trying to figure out if your truck will go into learn mode even if you have no sensors in your wheels.




I always bring my express van drama here. I’m fairly certain it falls in the NNBS category (2008 express NNBS style steering wheel and cluster).

I bought the van in 2019, the tpms system was working. I replaced the battery with an optima battery shortly after and the systems all reset. No readings from the TPMS system. Tried to relearn them and my van just would not go into learn mode. Searched the web with no luck. I let it go for months. In like 2020 I bought 4 new tires and I asked them if they could figure out why my sensors wouldn’t work. They called me and told me it would be like $500+ to even diagnose so I told them to just rip all the sensors out and install regular valve stems because 1 of the sensors was leaking anyway. I’ve chalked it up since then.

Fast foward to now. I’m exploring what I can do to try fix the issues. The information I’m receiving from other sites is that possibly the vehicle won’t even enter learn mode if no sensors are nearby/active. But no solid answers just speculation. I have my doubts because I have a hard time believing all 4 sensors went bad at the same time when I changed my battery in 2019.

If anyone who doesn’t have sensors installed could do me a solid and let me know if your truck will enter learn mode or just doesn’t respond when you try it. I’d greatly appreciate it.
 

Doubeleive

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Looking for a favor from anyone who lives life on the edge with no TPMS.

I’m trying to figure out if your truck will go into learn mode even if you have no sensors in your wheels.




I always bring my express van drama here. I’m fairly certain it falls in the NNBS category (2008 express NNBS style steering wheel and cluster).

I bought the van in 2019, the tpms system was working. I replaced the battery with an optima battery shortly after and the systems all reset. No readings from the TPMS system. Tried to relearn them and my van just would not go into learn mode. Searched the web with no luck. I let it go for months. In like 2020 I bought 4 new tires and I asked them if they could figure out why my sensors wouldn’t work. They called me and told me it would be like $500+ to even diagnose so I told them to just rip all the sensors out and install regular valve stems because 1 of the sensors was leaking anyway. I’ve chalked it up since then.

Fast foward to now. I’m exploring what I can do to try fix the issues. The information I’m receiving from other sites is that possibly the vehicle won’t even enter learn mode if no sensors are nearby/active. But no solid answers just speculation. I have my doubts because I have a hard time believing all 4 sensors went bad at the same time when I changed my battery in 2019.

If anyone who doesn’t have sensors installed could do me a solid and let me know if your truck will enter learn mode or just doesn’t respond when you try it. I’d greatly appreciate it.
it should go into learn mode and then eventually time out if nothing is synced, I think times out in like 2 minutes if no activity. same nbs, nnbs, k2
 

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