I've done a search and can't find much info. I am now certain my bcm is the reason for my rear access open message. Every time the message appears, I wiggle the connector on the bottom of bcm and the message always goes away. I got one out of an escalade from the junk yard, for parts or to reprogram. Has anyone removed/ replaced theirs. The one page I read mention cutting the dash frame in certain areas to aid in replacement. I'm assuming the whole dash has to come forward? thanks in advance.

 

The GM docs state to remove the instrument panel carrier first... That entails removing everything on the dash, then the entire dash frame. I've never looked into trying to remove the BCM on mine but sounds like quite a job. Keep us updated.

 

something to look over when you get it out. maybe worth checking on both for assurance. maybe look behind the fuse box on the drivers side panel for clearance

 

bronxteck's video link prompted me to look around and I found posted by by "thewonn" on YouTube. He describes removing the BCM (useful to you?) and also, rather interestingly, SP205 (Splice Pack 205) and his novel approach to fault finding.

This intrigued me further, so I extracted the wiring info for the class 2 serial data "Computer Data Lines Circuit" which includes SP205 amongst others. Looking at the circuit, any defective module connected to the serial data bus could potentially interfere with communications and this operation of all the other modules.

So disconnecting modules individually "one-at-a-time" seemed quite a good way of isolating a rogue control module, even though its tedious to do.

Food for thought maybe?

 

for me i was getting a high can bus 2 communication error it was because of the xm radio module. i removed it and got my can bus talking again. i had noticed that i was not getting any stations not even the free ones so figured i would start there.
it was this module tucked behind my 4 x 4 buttons on the side of the factory 6 cd changer radio https://www.sonicelectronix.com/pict...&picture_id=-1

 

There are a number of aftermarket modules that are excessively chatty on the communications bus. Disconnecting anything aftermarket should always be a first step in troubleshooting issue. ON a prior vehicle I had, my Tech2 would give frequent errors and my DiabloSport tuner would fail to communicate at all unless I first unplugged a cable on the aftermarket remote start module. I forget what brand it was but it controlled the door locks and monitored RPM on the CAN bus and apparently also put a lot of noise on the bus.

 

Ok thanks, the problem is intermittent, and the only issue I am having. I did change the radio but had the problem before also. I just ordered the tech 2. Is programming a bcm from another vehicle fairly straight forward with a tech 2?

 

I think you have to program it as a replacement and add your vin when it asks for verification. would probably be under special functions.

 

fastNYsix

You do have compelling evidence of either a dry joint inside the BCM, an intermittent connector or wiring issue.

If a connector/wiring issue, changing the BCM may not help, so if possible the best approach would be to find the root cause. Also its probably better to keep your existing BCM if possible.

Based on your "wiggle" description, the chance is are the BCM does have a bad joint.. According to the wiring information I have, there are two pins related to the "Lift Gate" as follows:-

1. B10 WHT (White) "LIFTGATE LOCK RELAY" Circuit 1304, CONNECTOR C3 - Output (probably not that)
2. A1 PNK/BLK (Pink & Black) "LIFT GATE AJAR SW SIG" Circuit 1303, CONNECTOR C6 - Input (more likely)

The service PDF's are a bit confusing and connector C6 is hard to trace, but I'm sure if you pull the BCM you'll find the related wire. It should then be a case of inspecting the circuit-board and re-soldering the bad pin, similar to bronxteck's very useful video.



MixManSC Might be able to guide you on programming, something I've never done (yet!) however I've included some GM programming info on the BCM plus some wiring details etc.

 

Thanks for all the help. I actually cut the pink black wire right near the bcm and the message won’t clear. I tried grounding, still no change. I’ll probably attempt to solder mine, and program the spare Escalade bcm as well. I’m not looking forward to pulling the dash out. Luckily It’s not my daily driver. The message doesn’t bother me, but I had to turn off the interior lights or they will never turn off on their own. And the compressor won’t run because it thinks the gate is open.