Continuity checks will just give you a resistance reading in ohms, typically good continuity is under 10 ohms. In the various harness checks I have done, its always been way less than 1 ohm... Its when your meter freaks out and says OL that you have a problem. I have done two GMT900 80e swaps now and have never had an issue like this. Have you looked at the NSS connector itself? Take it apart and see if one of the sockets has pulled back into the connector so that it isn't making a connection with the switch when plugged in.

 

OK good to know. I didn't know if I was looking for an exacrt reading

I've taken the nss apart 4 times already.

I will check the continuity.

THanks man

 

ANybody have a wiring diagram forthe bcm on a gmt900?

 

What are you looking for? The BCM has a lot of connectors.

 

The BCM is not Communicating with the ecm/tcm so I guess whatever diagrams would have that info. 1FastBrick is helping me out with it as i'm not electronically inclined. I'm not sure where the malfunction is and a diagram is really needed so we can see where the circuit has been interrupted.

Joseph got a U0140 code on his scanners.

U0140: Lost Communication With Body Control Module

The following GM service bulletin states:

Posted Image Service Information
2007 Chevrolet Silverado - 2WD | Sierra, Silverado (VIN C/K) Service Manual | Document ID: 2132689 #08-07-30-021A: Loss of High Speed GMLAN Communications, Intermittent No Crank/Door Lock Cycling, IPC Gauge Fluctuation, Transmission May Not Shift, DTCs (Repair Backed Out Terminal In Transmission Harness Connector) - (May 7, 2008)

Posted Image
Subject:Loss Of High Speed GMLAN Communications, Intermittent No Crank, IPC Gauge Fluctuation, Intermittent Door Lock Cycling, Transmission May Not Shift, DTCs U0073, U0100, U0101, U0102, U0121, U0140 Set (Repair Backed Out Terminal In Transmission Harness Connector)

Models:2007-2008 Cadillac Escalade Models, XLR
2007-2008 Chevrolet Corvette, Silverado, Suburban, Tahoe
2008 Chevrolet Tahoe Hybrid
2007-2008 GMC Sierra, Yukon Models
2008 GMC Yukon Hybrid

GM is suggesting checking the transmission connector

(Repair Backed Out Terminal In Transmission Harness Connector) - (May 7, 2008) . 6l80 and 6l90 and hybrid trans

Looking at the connector it seems to be fine. I still never found any breaks in the wire from the connector or other transmission wiring all the way up to about where the top of the bellhousing is. But I don't have xray vision so there is a definite possibility that i missed it or that the break is somewhere else maybe in the engine compartment area.

 

After searching countless hours for an answer to my dilemma, I found that a new case connector/wiring harness was put into the 4l80e in 2004. I put the old 03' case connector/wiring harness as well as the force motor in the new 07' trans and still no worky. I also just found out that the manifold pressure switch is different from 04'+ as well. I'll be testing that tomorrow.
When I ordered my ATSG manual, I asked for a manual for a 07 model 4l80e. The flaming 's over at ATSG said that "there have been no revisions to the 4l80e since 01". I'm not sure if the 03 mps and force motors can be utilized in both transmissions. 1 thing I do know is that the force motor connections are different so the wiring harness obviously is too. Who knows? There's got to be a reason when you type manifold pressure switch or internal wiring 4l80e on google, ebay etc. there is always an up to 03' or 04'+ option. If you look at the ATSG manual it says Updated March, 2003. In the index the last revision is in 01 for the overrun clutch. So they need to come out with a new version.

Someone please let me know if you have had issues swapping out your 80e for a newer or older unit. I am so tired of laying on the ******* cold concrete staring at the bottom of my inoperable truck. Seriously, I don't know when the last time I burned out was.


If you want my copy of the manual I'll sell it to you for $10. Whoever prints the manuals suck. It's hard to tell the way some parts go.

 

The transmission connector has nothing to do with GMLAN, I don't know why they would suggest that. Interesting that it lost BCM communication though... Do you have any way to swap in another TCM? GMLAN runs from the ECM through the TCM and then to the BCM. So if that TCM is toast, that would explain the loss of communication.

 

The TCM and the ECM are good and communicating with each other. I don't know if there is a High Speed GMLAN but I do think there are 2 tan wires at the connector so maybe they are apart of 2500 and 2501? I don't know. I'm thinking maybe any wire shorted out to the body can short out the bcm but then again I don't understand electronics and i'm slightly delirious being it's past 3:00am so

I id stumble across this though:

2007 CHEVROLET SILVERADO RECALL - #08V441000
RECALL FOR ELECTRICAL SYSTEM

GM IS RECALLING 857,735 MY 2006-2008 BUICK LUCERNE; CADILLAC DTS; HUMMER H2; MY 2007-2008 CADILLAC ESCALADE, ESCALADE ESV, ESCALADE EXT; CHEVROLET AVALANCHE, SILVERADO, SUBURBAN, TAHOE; GMC ACADIA, SIERRA, YUKON, YUKON XL, SATURN OUTLOOK; AND MY 2008 BUICK ENCLAVE VEHICLES EQUIPPED WITH A HEATED WIPER WASHER FLUID SYSTEM. A SHORT CIRCUIT ON THE PRINTED CIRCUIT BOARD FOR THE WASHER FLUID HEATER MAY OVERHEAT THE CONTROL-CIRCUIT GROUND WIRE.

as well as this

Body Control Modules and Ground Paths - GM Techlink

Body Control Modules and Ground Paths
By Blog Post on September 28, 2011 6:51 PM | No Comments
The Body Control Module (BCM) may be damaged if the module is supplied with battery power when the ground path is removed on some vehicles. The negative battery cable should be removed first before removing a BCM ground on 2006-2008 Monte Carlo; 2006-2011 Lucerne, DTS; 2006-2012 Impala; 2007-2009 SRX, Equinox, Torrent; 2007-2010 OUTLOOK; 2007-2012 Enclave, Acadia, Silverado, Sierra, Avalanche, Suburban, Tahoe, Yukon, Yukon XL, Escalade; 2008-2010 VUE, H2; 2008-2012 CTS, Express, Savana and Traverse models.

When the BCM is powered up (key in the Accessory or Run position) with the ground ring terminal removed or loose, the BCM will attempt to find a different ground path to the vehicle. This different ground path attempt may cause internal damage to the BCM.

The following systems controlled by the BCM may be inoperative or work intermittently because of an internally damaged BCM caused by a lifted BCM ground:

Interior lighting (will remain on or will not work)
Exterior lighting (will remain on or will not work)
Remote Keyless Entry
Door locks
Power windows and mirrors
Remote vehicle start
Remote trunk release


On 2007-2012 full-size pickups and utilities, the BCM can use two ground inputs. Both of these input pins (pins 1 and 5) are located on the X3 connector. The wires from these pins are tied to the same ground ring terminal in the vehicle. (Fig. 11)


The following is a specific list of vehicles and the components that the BCM ground wire passes through before going to the ground ring terminal.

TIP: Remove the negative battery cable if working one of these components.

2008-2010 H2 - Instrument panel electrical center
2008-2010 VUE - Instrument panel splice pack
2007 Silverado, Sierra, Avalanche, Suburban, Yukon, Escalade - Left instrument panel junction block


Refer to Bulletin #07-08-47-004D for additional information. Models listed in the bulletin and not referenced above have the BCM ground wires going directly from the BCM to the ground ring terminal.

Anybody have similar problems due to these recalls?

 

Oh and here are the Fuses that are not getting power from either side but the fuse is still good

MINI BUS FUSES
1 TRLR STOP RT (10A)
2 EXH VLV (30A)
4 TRLR STOP LT (10A)
8 FRT WASH (15A)
11 TRLR BCK/PU (10A)
12 LO HDLP –LT (10A)
16 VEH BCK/UP (10A)
17 LO HDLP-RT (20A)
18 A/C CMPRSR (10A)
21 FUEL PUMP (20A)
24 REAR WASH (15A)
26 TRLR PRK (15A)
27 LT PRK (15A)
28 RT PRK (15A)
29 FOG LAMP (15A)
30 HORN (15A)
31 HI HDLP-RT (10A)
32 DRL (15A)
33 HI HDLP-LT (10A)
34 DRL 2 (15A)
51 CHMSL (15A)
52 REAR DEFOG (30A)
53 HTD MIR (15A)

FUSE PANEL ON DRIVER SIDE BETWEEN DOOR AND DASH
UNLOCK2
SWC BCLT
DRV UNOCK
LOCK2
UNLOCK1
BCM (10A) FUSE HAS POWER

 

Outside of the EPC changing in 04 and the wiring harness change to accommodate this the manifold switch is still the same one its always been. Using the late or early set up is not an issue and I have personally done it in the past without an issue. Now I'm not sure if I read this correctly but did you say you have a bunch of fuses that do not have power? If this is the case I would correct this before doing anything else. Find out where the power supply comes from and figure out why its not completing these circuits.