1999 pcm Help(os 9365637)

[tt03]

Looking for help, so I have a 1999 pcm from a Silverado 1500 4x4 with a lm7. I am wanting to change the transmission to a 4l80e as well as convert it to a 4x2. Can anyone lead me in the direction to do so? I have looked extensively everywhere to find an xdf or even what to update the os to however cannot find anything. My os is 9365637, all responses and help is appreciated very much, thanks!

[B52Bombardier1]

Hello,

In all likelihood, you will be overwriting and abandoning your 9365637 OS and replacing it with something else such as 12212156 that should work with your 1999 PCM. Certainly, make a copy of your 9365637 OS but you will soon say goodbye to it.

Try to segment swap a 5.3 liter LM7 2002 Silverado 12212156 and bring in the 4L80E from an Express van that also used 12212156. I have used LS Droid for my segment swaps.

For 4x2 conversion operation (I have no experience here), I should think that you will need to kill off the 4x4 DTC codes, if any. Although, I can't find any 4x4 information in 12212156 after a quick look. So, this might be relatively easy.

Rick

[dave w]

Maybe the attached .bin will help? Use at your own risk

Modified means . . . It's NOT STOCK!

dave w

[B52Bombardier1]

That BIN shows up as a 6.0 on Tuner Pro RT here when using the 2156 XDF. Is it 2156-based for the OS?

Edit: Yes, looks to be 2156 based but a 6.0 engine.

Rick

[dave w]

Hmmm, maybe it wasn't such a good idea to post a Modified.bin file?

Hmmm, maybe the factory only offered the 4L80E with the 4.8 Liter and 6.0 Liter?

Hmmm, maybe the attached .bin files can be used for Segment Swaps?

dave w

Read Original LM7 5.3 Liter:
VIN: 3GNFK16T42G221019
OS: 12212156
Engine 5.3 Liter / LM7
Transmission: 4L60E
VIN K1 decodes to 4WD

Read Craigs 2002 6.0 Liter:
VIN:1GTGC24U42Z119117
OS: 12212156
Engine: 6.0 / LQ4
Transmission: 4L80E
VIN C2 decodes to 2WD

[kur4o]

If you are upgrading 99-00 OS to 01+ OS, you need to clone the pcm or it will be semi-bricked due to eeprom data difference.

[brian617]

For 4x2 conversion operation (I have no experience here), I should think that you will need to kill off the 4x4 DTC codes, if any. Although, I can't find any 4x4 information in 12212156 after a quick look. So, this might be relatively easy.

Rick

Nothing needs to be done for 4x4 that I'm aware of. If there is no 4x4 low input the 4x4 low tables wont be used. 4x4 DTCs will be in the TCCM