I suspect BCM... thoughts?

[Geotrash]

Yeah it's been a pain trying to find the issue. What's so weird is if I immediately disconnect and reconnect the battery, all is fine. I've been inspecting the wiring everywhere I can, repaired one section that was causing a different problem.

My codes pop on both the high-speed and low-speed networks. There is one common denominator... the VCIM (onstar) module. Both networks go through it. I may just try and find a used one to swap in and see what happens. It's just unfortunate that I cannot replicate the problem reliably. It happens when it wants to.

The Onstar module terminates the CANbus network so all modules depend on it. I believe it's in the center console and may be worth swapping out.

 

[Rocket Man]

The Onstar module terminates the CANbus network so all modules depend on it. I believe it's in the center console and may be worth swapping out.

Yep and you can’t remove it or all communication goes down, I found that out when I wanted to be rid of it. I had to put it back in. I removed the coax that went to the shark fin instead so it can’t work but the module itself had to stay.

 

[petethepug]

You already addressed some of these issues but here’s the TSB that hits the entire group of issues during these years.

Finding GMLAN wiring problems

Some owners of 2007-2010 Cadillac Escalades, Chevy Avalanche, Silverado, Suburban and Tahoe, and GMC Sierra, Yukon, Yukon XL, Yukon Denali and Yukon Denali XL vehicles may complain about issues ranging from: IPC indicators on, gauges inoperative, no crank, harsh transmission shifting, no...

www.autoserviceprofessional.com

 

[me88]

The Onstar module terminates the CANbus network so all modules depend on it. I believe it's in the center console and may be worth swapping out.

I wonder how mine is wired then since it never had OnStar/Bluetooth (VCIM) from the factory (RPO Code UE0). It came with a Talk button on the steering wheel but that only muted the stock radio. There are no plugs under the radio with loopback jumpers or something like that installed. Tech2 complains about the missing VCIM in the beginning but it scans every module without problems.

 

[George Owens]

Yea I’m still having this issue, I haven’t been driving seeing as though I had a vasectomy last week. I did manage to drive to Jersey and back to Philly with no issues yesterday. I will try to look behind the brake pedal because I noticed it seems to also happen when I’m doing something with the brakes sometimes

 

[George Owens]

Could anyone point me in the direction of a wiring chart for the can bus by any chance?

 

[Geotrash]

Could anyone point me in the direction of a wiring chart for the can bus by any chance?

High speed bus page 1:


High speed bus page 2:


Low speed bus page 1:


Low speed bus page 2:


Low speed bus page 3:

 

[Geotrash]

Serial data communication and wake-up circuits:


Linear interconnect network (LIN) Bus:

 

[petethepug]

Now that’s a supporting member! Bam