Where can I locate the transmission control unit for a 2012 Chevrolet Express cargo van 6.0L V8 2WD?
Chevrolet Express cargo van intermittently fails to start. Battery is full power and when you go turn the key from accessory on to starting all lights go off on the dash. There is no noises at all. This will continue to happen for at shortest 10 minutes or enough to get a tow and then start by the time it makes it the mechanics. It also intermittently will just turn off while driving. You can be just driving and you lose power steering and realize the engine is just off. doesn't give any signal. Doesn't stutter, just loses power. When either of these scenarios happen, it pops codes U0100 & P0700. These codes usually clear themselves within 50 miles. The van will also go a couple days without any issues or have issues multiplied times in one day. It's been to multiple dealerships and mechanics. We've checked all the, have changed ECM and BCU. Since we're getting the P0700, I would like to try a new TCU. If anyone has an idea where it's located or any other ideas would be really appreciated.
Thanks

 

far passenger side of the engine compartment.
But if I were you, instead of firing the parts cannon at it again, I get a proper diagnosis from a competent mechanic first. Make sure the module is getting good power, ground, and data signal.
Dealers are worthless. You may need to go to an auto electrical specialist.
Otherwise you'll be back at square one, only $700 poorer. The module has to be programmed.
Schematics are on gmupfitter.com

 

I have added the pictures and hopes you can help me point the right direction to tcu. I cannot find it

Thanks again for all your help

 

on my 2013 1500 AWD, it's right here, but it seems yours is different.
Go to gmupfitter.com and download the electrical manual. For sure it'll be in there.

 

Schematics from the upfitter manual for 2015 with 6L90 trans show the transmission control module inside the transmission.

 

It also says this so maybe there looks like there is more than one? Looks like where mountainmanjoe said.

K71 Transmission Control
Module

M30 Attached to the right inner
fender, near the A/C-Heater
case

Engine Compartment K71 Transmission Control
Module(M30)

 

Yah looks like TCU is this one is inside the transmission, so not attempting to replace that. all grounds and battery cables have been cleaned/checked. New battery, Battery Cables, Starter, BCU, ECU, Ignition switch, ignition cylinder. The no start issue is never present after being off over night. Always show's up after its been in use for over 4 hours. The not start usually does not lass longer then 10 minutes so hard to take it to a shop. At such a loss and the problem will not stay an issue and is intermittent. We have 8 of these express vans and this is the first time we have had an issue like this.

You Tube

 

Will it start in Neutral when this happens?

this might be of some help

 

I had a TCU go out, and the van still started and drove. I think it's unrelated.
Grab some schematics from gmupfitter.com and start tracing and probing your startup circuits

 

When it won’t start see if service engine light is on with key in the on position.
It probably isnt.
Fuse boxes on these vehicles have little wire mazes inside the two fuse box halves.
After vehicle gets hot wires. Lose connection.
usually to run crank fuse.
sometimes to ac relay
this will give you both codes U 1000,P0700
trans banging,skipped shifts,hard shifts
Fuse box is around 200 new from Gm.
next time pull fuse box coverr wiggle box it will probably start.