'07 Yukon XL Denali w/ Multiple Wiring Issues

[j91z28d1]

how in depth do you want to go and how much money do you want to spend?

at this point if you subscribe to all-data, they have a monthly diy version that's just like the shop software but only tied to one vin. this will give you trouble trees to follow thru the system. Will start with no start and the basics and have you tracing wires all thru the harnesses and ways to test modules before replacing them as a guess. but you will most likely need a good scanner that can activate things. like your rear door locks don't work, is it a switch or bcm. scanner can send the request thru the obd2 port. that will split the fault in half and then it will go from there. cheapest being a clone tech 2 from China for about 300$. big name stuff that can do all the tests it's going to ask for is probably 1k and up.

it's been a while and you've done a lot, but I think this one is going to take some good tech work to fix. sadly you won't find many good techs in shops these days, money making parts swapper mostly.


for a reference you can watch some of the trouble shooting done by the YouTube guy at south main auto. get an idea of the type of stuff the software is going to lead you.

only thing annoying about the tech 2 is I haven't seen where I can graph out the can bus data like you'll see him do on the high end scanners. seems like it might be helpful, but I don't know if it's needed and maybe the tech 2 can, I just haven't learned to do it.


as for bcm that doesn't need programed, no clue how those work. if you want to buy a used one either junk yard or ebay and program it yourself. cheapest I've found. as long as you have a good laptop with new windows on it, cause the gm site is picky about new enough computers. I had to borrow a work laptop, or I'd have had to take my home pc in the garage lol. but pass their dongle is 140$ from OBDxpro gt and then acdelco site was 45$ to license one vin for 2 years. you can flash and or update any module in the truck with that. the gm site is annoying and will be frustrating while you watch YouTube videos on how to make it work lol.

leave to gm to somehow make their software site that every tech needs access to be a cluster to use and take 3 times before a flash works haha.


good luck. may the force be with you.

 

[tegimaster]

Since this is my wife's car and we still owe ~$7,000 on it I have to fix it one way or another. The fact that it's the only rig we own that can fit the whole family, and is the only one with AC the sooner the better. Doesn't make it hurt any less but it is what it is.

So to ensure I have all the purchases and steps in the correct order, I need to buy:
- Subscription to All-Data
- Tech 2 Scanner
- OBD passthrough dongle
- ACDelco passthrough license for GM
- Replacement BCM

Is a used module really OK to reflash? I've seen reports online that they won't reflash.

Highway71autoparts has a replacement pre-flashed BCM for $212. But their site says "Air Bag warning light may remain ON until "Setup SDM Primary Key in BCM" is performed using a scan tool capable of doing this procedure. On some vehicles a brake pedal relearn will also need to be done." Would that apply to my '07 or is that more of a generic warning?

Anything over $100 will take me a month or two to save up for so this will be a slow process, but since we have no good general auto shop and no dealer this is my only option.

Thanks for the reply, I'll try to keep this up to date as I work through it.

 

[Doubeleive]

Since this is my wife's car and we still owe ~$7,000 on it I have to fix it one way or another. The fact that it's the only rig we own that can fit the whole family, and is the only one with AC the sooner the better. Doesn't make it hurt any less but it is what it is.

So to ensure I have all the purchases and steps in the correct order, I need to buy:
- Subscription to All-Data
- Tech 2 Scanner
- OBD passthrough dongle
- ACDelco passthrough license for GM
- Replacement BCM

Is a used module really OK to reflash? I've seen reports online that they won't reflash.

Highway71autoparts has a replacement pre-flashed BCM for $212. But their site says "Air Bag warning light may remain ON until "Setup SDM Primary Key in BCM" is performed using a scan tool capable of doing this procedure. On some vehicles a brake pedal relearn will also need to be done." Would that apply to my '07 or is that more of a generic warning?

Anything over $100 will take me a month or two to save up for so this will be a slow process, but since we have no good general auto shop and no dealer this is my only option.

Thanks for the reply, I'll try to keep this up to date as I work through it.

IF you really think it is the BCM then you are better off just getting the vin programmed one, the airbag light won't prevent you from driving it, the brake pedal relearn might but I have never heard of that,
the $45 sps license includes access to the software to do programming of any modlule but no diagnostic. the only module you cannot reprogram is a SRS module if an airbag was deployed from a accident (you would need another module from a non-wrecked vehicle or a new one). as far as I know that is the only case where you could not reprogram a module.
you need a decent laptop to run the software with windows 10 64bit, 500gb free space, 8gb ram but the more the merrier
and you need a pass thru tool like a mdi2 clone
the gm software can be a real pain, you have to run everything as ADMIN from the get-go including the Broswer or wont install properly and work
might take numerous tries even then to get it installed properly
double check what you soldered on, if you suspect it could be a problem then unplug the drivers door switch and see if that changes anything.

 

[Doubeleive]

This is my first post so I apologize if there's an answer for this elsewhere, I've just spent all day trying to resolve my issue and I'm at my wit's end.

Tl;dr at end.

Backstory:
My wife and I bought a 2007 GMC Yukon XL Denali a couple years ago. 151It died in the middle of its test drive which should've been our red flag but the dealer spent 2 weeks "having all the engine sensors replaced" and a 2nd test drive went without issue so we bought it anyways.
Since we started driving it home (4 hr trip) it's intermittently thrown "Service Traction Control/Service Stabilitrak" error codes on the dash. It also randomly throws a "Camshaft Position Sensor" check engine light code, but only when the other Stabilitrak light is active. If the Stabilitrak service light goes out long enough the check engine light goes out too.
I have replaced the entire rear air shock suspension system, cleaned the front engine compartment fuse box, and replaced the throttle position sensor, brake position sensor, brake light sensor, engine-to-frame ground strap, and about half the fuses in the 2 main fuse boxes. I have also replaced the O-Ring for the oil pick-up tube.
While driving I have noticed that the transmission shifts harder when the "Service Traction Control/Stabilitrak" light is on. Primarily it seems to the the 1-2 gear shift, but I am not 100% certain.

Today:
All of the switches on the driver's door quit working while running errands in town. When we got home I looked at the wires in the hinge and noticed the black one had been patched with a solder-less crimp connector and had broken at the edge of that connector.I disconnected the battery, cut the connector out, and soldered the wires together. When I re-connected the battery (it was maybe an hour due to multitasking) the dash errors were still present along with "Door Ajar" as I expected, but also "Park Assist Off."

I thought that was weird so I went to start it and the car wouldn't crank, start, or otherwise respond to my attempts to start. I thought maybe the trunk being open was a culprit but the trunk wouldn't close either.

I got my code reader (Not Tech2) and it said "U0140-00 Lost Communication With Body Control Module" which explains why it won't crank or anything.

I've seen lots of people posting similar issues, but only a few that I really felt was my issue. I suspect that somehow in fixing a wire for my driver's door and/or disconnecting and connecting the battery... I fried my BCM? I see a few who agree that this is a thing that can happen, but did it happen to me?

I traced fuses for the modules in question and replaced them all, removed my BCM, cleaned contacts, and re-connected. I unplugged my battery, touched the cables together, and let it sit for an hour. No change.

Attached are pictures of all error messages on my dash as well as my code reader.

Is it possible that I've missed something in my troubleshooting?

D I have to replace my BCM? If that's the case I'm in for a treat because the closest GM dealer is ~2 hours away and I'm too poor to have the car towed to say the least about dealer fees for that sort of work.

I've seen posts and talk about buying used/aftermarket BCMs and flashing it at home, but I also see people saying that it doesn't work anymore.

TL:dr:

Poor man solders broken wire in driver's door of '07 Yukon XL Denali and fries BCM? Too poor for very distant dealer to fix. Help!

what part of oregon are you in?

 

[tegimaster]

I'll check on unplugging the door when I get home from work today. I feel like I've already tried that once and it didn't change anything, but that's been a month now.

My assumption is that somehow the soldering job fried a computer. Be it when I soldered the wires together or when I reconnected the battery after I finished soldering. It was the big black wire that I had to solder. It was crimped with a solderless connector and broke on the edge if the connector.

With everything that isn't working now I do feel confident that it's the BCM now. No locks, no windows, no tailgate unlocking or opening, no crank, and OBD2 saying it can't communicate with the BCM.

If I have to get a Tech 2 scanner I can, just not this month. The replacement BCM is a bit cheaper, and I'm curious if its replacement might fix my Stabilitrak issues I was having beforehand.

 

[tegimaster]

what part of oregon are you in?

Klamath Falls.

 

[mikez71]

Might be worth checking the starter just in case the wire fell out. The clip that holds it in breaks easily when removing.
Sounds like you had some other problems to begin with, so just in case the starting is separate from the other issues..
Looking through the passenger fender liner with the wheel cranked and you can see/reach it.

I really don't think soldering on the ground wire with battery disconnected would do it. maybe welding on it..?
If not the BCM, then the network wires to or before the BCM maybe? IDK good luck and keep us updated!

Just thrrew this pic in as an example, the network is connected to park assist, vass (door modules), rollover sensor

 

[Doubeleive]

I'll check on unplugging the door when I get home from work today. I feel like I've already tried that once and it didn't change anything, but that's been a month now.

My assumption is that somehow the soldering job fried a computer. Be it when I soldered the wires together or when I reconnected the battery after I finished soldering. It was the big black wire that I had to solder. It was crimped with a solderless connector and broke on the edge if the connector.

With everything that isn't working now I do feel confident that it's the BCM now. No locks, no windows, no tailgate unlocking or opening, no crank, and OBD2 saying it can't communicate with the BCM.

If I have to get a Tech 2 scanner I can, just not this month. The replacement BCM is a bit cheaper, and I'm curious if its replacement might fix my Stabilitrak issues I was having beforehand.

the stabiltrack issue is more likely related to the crank position sensor error, and not the BCM
a tech2 would allow you to "relearn" the sensor if that happened to be all it needed but since It is a 07 it might be time for a new sensor
you can jumper the starter relay in the engine bay fuse box, be sure it is in park or neutral before doing so, which by the way could also be a reason for no start if the computer thinks it is in gear so just something to double check.
with all your current multiple issues it would be wise to check all power and grounds and be sure the battery is charged and has at least 10.5v bare minimum when the key is turned to start. 10.5v is technically dead, but is also the voltage cut-off point operational wise.

 

[tegimaster]

I've been wondering about that sensor.

Before we bought the car we did a test drive and it died at a stoplight. Limped it back to the dealer and they spent 2 weeks "replacing all engine sensors" which seemed to fix it but the light and error came back when driving home.

So is it more true that the sensor is throwing the code, not the stabilitrak causing the sensor to code?

 

[Doubeleive]

I've been wondering about that sensor.

Before we bought the car we did a test drive and it died at a stoplight. Limped it back to the dealer and they spent 2 weeks "replacing all engine sensors" which seemed to fix it but the light and error came back when driving home.

So is it more true that the sensor is throwing the code, not the stabilitrak causing the sensor to code?

a stabiltrak error is a syptom from other issue's such as abs, transmission, engine, suspension.