M1045A2 4L80E Transmission Wiring Problem

[TexasFlu419]

I received a box from Gov Planet today, containing a replacement TCM, and the breaker/relay wiring box with the wiring that comes out of it (pic attached). Since there are five wires in the bundle from the breaker/relay, and the bundle in the trans tunnel only has four, I am assuming one of the five goes off to the battery, and the other four connect to the bundle in the trans tunnel? If that is correct, I need to know where the other end of the those four trans tunnel wires are located, so I can run a continuity test on them for identification. Any info?

If there is another way to identify the four wires, please let me know.

Thanks again.

 

[TexasFlu419]

I finally figured out the wiring. Hopefully no one will have this problem, but I wanted to get the thread complete, just in case they do.

The five wires coming from that bundle are:

Wire 1 - 290/291/537/537B/537C - This wire connects to the positive battery terminal, providing 12V

Wire 2 - 290A/291A/537A - Connects to one of the four trans tunnel wires, 537D, going to the TCM. You can figure out which trans tunnel wire by checking connectivity to terminal D on the J2 connector of the TCM.

Wire 3 - 57T - Connects to the ground shunt in the battery box. The second of the four trans tunnel wires, 599B, also connects to the shunt, and you can identify it by checking connectivity to terminal F on the J2 connector.

Wire 4 - 290C/291C - Connects to the third of four trans tunnel wires, 291D, which goes to the TCM. This was a pain to trace, as I had to look at the bundle of wires going into the TCM connector, then estimate which hole 291D was in, but eventually found connectivity.

Wire 5 - 29T - Connects to the fourth of four trans tunnel wires, 27, which goes to all sorts of electrical points. It is the easiest to trace, as you can find connectivity at the 27 wire that goes into the bottom of the wiper motor.

Hope this helps, and thanks to all those who helped me.

 

[Grumpy6x6]

I finally figured out the wiring. Hopefully no one will have this problem, but I wanted to get the thread complete, just in case they do.

The five wires coming from that bundle are:

Wire 1 - 290/291/537/537B/537C - This wire connects to the positive battery terminal, providing 12V

Wire 2 - 290A/291A/537A - Connects to one of the four trans tunnel wires, 537D, going to the TCM. You can figure out which trans tunnel wire by checking connectivity to terminal D on the J2 connector of the TCM.

Wire 3 - 57T - Connects to the ground shunt in the battery box. The second of the four trans tunnel wires, 599B, also connects to the shunt, and you can identify it by checking connectivity to terminal F on the J2 connector.

Wire 4 - 290C/291C - Connects to the third of four trans tunnel wires, 291D, which goes to the TCM. This was a pain to trace, as I had to look at the bundle of wires going into the TCM connector, then estimate which hole 291D was in, but eventually found connectivity.

Wire 5 - 29T - Connects to the fourth of four trans tunnel wires, 27, which goes to all sorts of electrical points. It is the easiest to trace, as you can find connectivity at the 27 wire that goes into the bottom of the wiper motor.

Hope this helps, and thanks to all those who helped me.

What was the transmission doing before you found the problem? I have been trying to figure out my M1123 with the 4L80E for weeks now. At the beginning the toque converter stayed locked. I was told to make sure the fluid was in the hash marks. It wasn't so I added fluid. Now it is intermitting, sometimes the torque converter will lock in 1st-3rd gear and stall the motor when you press the brake pedal and other times it will act normal.

 

[Panchotheking]

Call my shop...I wire these trucks weekly.
i can tell you where all these wires terminate too...

Whats your number?

 

[Mogman]

What was the transmission doing before you found the problem? I have been trying to figure out my M1123 with the 4L80E for weeks now. At the beginning the toque converter stayed locked. I was told to make sure the fluid was in the hash marks. It wasn't so I added fluid. Now it is intermitting, sometimes the torque converter will lock in 1st-3rd gear and stall the motor when you press the brake pedal and other times it will act normal.

Have you inspected the TCM for water intrusion?
Are you saying when not moving but when in gear, then you press the brake and it stalls? or are you saying when you come to a stop it stalls?
This is possibly a bad TCM, the TCM should never try to lock the T/C in 1st gear.